docs: changelog section for the process-kill feature and agent dead-process fix

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/build-deb.yml

@@ -1,10 +1,10 @@
 name: Build Debian Packages
 
 on:
+  # APT publishing is release-driven: we build + publish only on `v*` tag
+  # pushes. PRs into master still build the .debs as a sanity check (no
+  # publish). Manual dispatch is kept as an escape hatch.
   push:
-    branches:
-      - master
-      - feature/debian-packaging
     tags:
       - "v*"
   pull_request:
@@ -231,7 +231,9 @@ jobs:
     name: Publish to APT Repository
     needs: combine-artifacts
     runs-on: ubuntu-latest
-    if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/v')
+    # Publish only on `v*` release tags — keep gh-pages stable between
+    # releases instead of overwriting same-version .debs on every commit.
+    if: startsWith(github.ref, 'refs/tags/v')
     permissions:
       contents: write
     steps:
@@ -340,16 +342,18 @@ jobs:
           GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
         run: |
           if [ -n "$GPG_PASSPHRASE" ]; then
-            echo "$GPG_PASSPHRASE" | gpg --batch --yes --passphrase-fd 0 \
+            echo "$GPG_PASSPHRASE" | gpg --batch --yes --no-tty --pinentry-mode loopback --passphrase-fd 0 \
               --default-key "$GPG_KEY_ID" \
               -abs -o dists/stable/Release.gpg dists/stable/Release
-            echo "$GPG_PASSPHRASE" | gpg --batch --yes --passphrase-fd 0 \
+            echo "$GPG_PASSPHRASE" | gpg --batch --yes --no-tty --pinentry-mode loopback --passphrase-fd 0 \
               --default-key "$GPG_KEY_ID" \
               --clearsign -o dists/stable/InRelease dists/stable/Release
           else
-            gpg --batch --yes --default-key "$GPG_KEY_ID" \
+            gpg --batch --yes --no-tty --pinentry-mode loopback \
+              --default-key "$GPG_KEY_ID" \
               -abs -o dists/stable/Release.gpg dists/stable/Release
-            gpg --batch --yes --default-key "$GPG_KEY_ID" \
+            gpg --batch --yes --no-tty --pinentry-mode loopback \
+              --default-key "$GPG_KEY_ID" \
               --clearsign -o dists/stable/InRelease dists/stable/Release
           fi
           gpg --armor --export "$GPG_KEY_ID" > KEY.gpg

.gitignore

@@ -1,6 +1,7 @@
-/target
+# Any crate's build directory, including standalone sub-crates
+# (zellij_socktop_plugin, socktop_wasm_test) that live outside the workspace.
+target/
 .vscode/
-/socktop-wasm-test/target
 /.cargo/
 
 # Documentation files from development sessions (context-specific, not for public repo)

CHANGELOG.md

@@ -0,0 +1,64 @@
+# Changelog
+
+## 1.60.0 — unreleased
+
+Everything since `v1.50.0`. Applies to all three crates (`socktop`, `socktop_agent`, `socktop_connector`), which move to 1.60.0 together.
+
+### Security
+
+- **Certificate pinning is now real.** With `--verify-hostname` off (the default), the client previously accepted *any* server certificate — the `--tls-ca` file was never consulted. The presented certificate must now be byte-identical to one in the pinned PEM (multi-cert files supported for rotation). If you use TLS, update the client: earlier versions are MITM-able despite the pinning documentation. (housekeeping-p2)
+- `key.pem` is created with mode 0600 (was world-readable 0644); agents also tighten existing keys on startup. (housekeeping-p2)
+- The agent's per-PID caches now evict (60s age / 64 entries); previously they grew without bound. (housekeeping-p2)
+
+### Performance
+
+- Agent CPU on GPU machines cut ~6× (measured 23.5 → 4.0 ms/s at default polling): GPU collection moved to a dedicated worker thread that keeps the NVML session open instead of re-initializing it every 1.5 s on the async runtime. (housekeeping-p2)
+- `journalctl` no longer blocks the agent's async workers. (housekeeping-p2)
+- Cached "no temp sensor / no GPU" results count as fresh — no more per-request rescans on hosts without them. (housekeeping-p2)
+- Nagle disabled on all connection paths (small request/response frames). (housekeeping-p2)
+
+### TUI
+
+- **Compact layout for small windows**: when the window is too short for the Disks pane, Disks is dropped, Memory/Swap go side by side, GPU collapses to one line (omitted if absent), and the reclaimed rows keep the CPU graph and per-core bars visible. `--compact` pins it. (#37)
+- **Width-aware text**: header, CPU title, and process table shed detail by priority as the terminal narrows instead of overwriting each other; process Name column is now the last to go, not the first. Fixed sort-header clicks landing up to 4 columns off. (#38)
+- **Responsive input**: keys and mouse are handled within ~30 ms instead of queueing for a full metrics interval. (housekeeping-p2)
+- **No more freezes**: all requests carry a 5 s timeout; a dead connection shows the reconnect modal (with working `q`) instead of hanging the UI. Consecutive timeouts surface a persistent "agent not responding" error. (housekeeping-p2)
+- Old agents without the per-process endpoints once again show "Agent Update Required" instead of a reconnect loop. (housekeeping-p2)
+- Journal pane distinguishes "no entries" from "no journal access" (e.g. user-run/demo agents) and shows journalctl's hint plus the fix. (housekeeping-p2)
+- Scatter-plot axes align correctly for large CPU-time values. (housekeeping-p2)
+- Demo mode explains how to install `socktop_agent` when the binary is missing. (#36)
+
+### Correctness
+
+- Process/child CPU times were sent as ms but displayed as µs — values rendered 1000× too small in the details modal. (housekeeping-p2)
+- Non-Linux per-process CPU% no longer truncates multi-core usage (clamp after divide). (housekeeping-p2)
+- Journal timestamps are real RFC 3339 UTC with numeric sorting (additive `timestamp_us`). (housekeeping-p2)
+- Partition detection uses `/sys/block` on Linux — whole-disk filesystems (`nvme0n1`, `zram1`) are no longer misclassified as partitions. (housekeeping-p2)
+- Network rates use agent-side sample timestamps (additive `sampled_at_ms`), eliminating rate sawtooth from TTL-cached snapshots; falls back to the client clock with older agents. (housekeeping-p2)
+- The details modal's Command/exe/cwd fields are populated again (dropped by an earlier refresh optimization). (housekeeping-p2)
+- Non-ASCII device names no longer panic the disk pane. (housekeeping-p2)
+
+### Wire format (additive only — old/new client-agent pairs keep working)
+
+- `Metrics.sampled_at_ms` (epoch ms of actual collection)
+- `JournalEntry.timestamp_us` (epoch µs), `JournalEntry.timestamp` now RFC 3339
+- `JournalResponse.notice` (journal-access hint)
+
+### Internal / packaging
+
+- ratatui 0.28 → 0.30 (#33); aws-lc-rs advisories patched (#34); Debian packaging for the agent (#25); assorted dependabot bumps.
+- ~3,100 lines of dead code removed, including an orphaned pre-refactor copy of the connector.
+- `socktop` consumes `socktop_connector` via a path+version dep — connector changes are testable in-repo before publishing.
+- wasm examples build against the in-repo connector; note `zellij_socktop_plugin` has pre-existing compile errors and needs its own rework.
+
+### Process kill (PR #40)
+
+- **Kill a local process from the TUI** (`t` on a selected process, or inside Process Details): btop-style Terminate/Force-kill confirmation. Local agents only — the signal is sent by socktop itself with its own privileges, never over the wire; remote agents never show the option. PID-reuse guarded (the confirmed name must still own the PID at signal time).
+- **Agent no longer reports dead processes**: a long-lived sysinfo `System` accumulated every process ever seen (21k+ entries on a 289-process host), inflating memory, per-poll work, and the process count — and keeping killed processes on screen forever. Update agent and client together on machines where the kill feature will be used.
+- Killed rows leave the list when the process actually exits and cannot be resurrected by cached agent snapshots; details views for dead processes close themselves, including through parent-navigation chains.
+- Selection hint no longer vanishes for long process names; confirmation/info dialogs size to their content.
+
+### Upgrade notes
+
+- **Release/publish order**: `socktop_connector` → `socktop` → agent packages.
+- Clients older than 1.60 work against 1.60 agents and vice versa; the security fix is client-side, so prioritize client updates where TLS is used.

Cargo.toml

@@ -24,8 +24,9 @@ serde_json = "1.0"
 sysinfo = "0.37"
 
 # CLI UI
-ratatui = "0.28"
-crossterm = "0.27"
+ratatui = "0.30"
+crossterm = "0.29"
+unicode-width = "0.2"
 
 # web server (remote-agent)
 axum = { version = "0.7", features = ["ws"] }

README.md

@@ -5,6 +5,8 @@ socktop is a remote system monitor with a rich TUI, inspired by top/btop, talkin
 - Linux agent: near-zero CPU when idle (request-driven, no always-on sampler)
 - TUI: smooth graphs, sortable process table, scrollbars, readable colors
 
+[socktop.io](https://www.socktop.io) 
+
 <img src="./docs/socktop_demo.apng" width="100%">
 
 ---
@@ -29,6 +31,8 @@ socktop is a remote system monitor with a rich TUI, inspired by top/btop, talkin
   - Only top-level processes listed (threads hidden) — matches btop/top
 - Optional GPU metrics (can be disabled)
 - Optional auth token for the agent
+- Compact layout for small windows: automatically drops the panes that no longer fit so
+  the CPU graph and per-core bars stay visible (see [Compact mode](#compact-mode))
 
 ---
 
@@ -211,6 +215,8 @@ socktop --verify-hostname --tls-ca /path/to/cert.pem wss://HOST:8443/ws
 # shorthand:
 socktop -t /path/to/cert.pem wss://HOST:8443/ws
 # Note: providing --tls-ca/-t automatically upgrades ws:// to wss:// if you forget
+# force the small-window layout at any terminal size (normally automatic):
+socktop --compact ws://HOST:3000/ws
 ```
 
 Intervals (client-driven):
@@ -222,6 +228,29 @@ The agent stays idle unless queried. When queried, it collects just what’s nee
 
 ---
 
+## Compact mode
+
+In a short terminal the fixed layout runs out of rows and the CPU graph and per-core bars
+are the first things to collapse — exactly the panes you are most likely watching. Once
+the window is too short for the Disks pane to show even one disk, socktop switches to a
+compact layout:
+
+- **Disks is dropped.** It is the pane that degrades worst when partially drawn.
+- **Memory and Swap move side by side** into the row Disks vacated.
+- **GPU shrinks to a single line** — utilisation and VRAM only, no device name. On a host
+  with no GPU the pane disappears entirely.
+- **Everything reclaimed goes to the CPU graph and per-core bars**, which stay usable well
+  below the size where they used to vanish.
+
+The switch is automatic and needs no configuration. Pass `--compact` to pin the compact
+layout at any window size:
+
+```bash
+socktop --compact ws://HOST:3000/ws
+```
+
+---
+
 ## Connection Profiles (Named)
 
 You can save frequently used connection settings (URL + optional TLS CA path) under a short name and reuse them later.
@@ -387,6 +416,7 @@ Tip: If only the binary changed, restart is enough. If the unit file changed, ru
 
 ```json
 {
+  "sampled_at_ms": 1786752000123,
   "cpu_total": 12.4,
   "cpu_per_core": [11.2, 15.7],
   "mem_total": 33554432,
@@ -446,7 +476,7 @@ socktop --tls-ca /path/to/agent/cert.pem wss://HOST:8443/ws
 Notes:
 - Do not copy the private key off the server; only the cert.pem is needed by clients.
 - When --tls-ca/-t is supplied, the client auto‑upgrades ws:// to wss:// to avoid protocol mismatch.
-- Hostname (SAN) verification is DISABLED by default (the cert is still pinned). Use `--verify-hostname` to enable strict SAN checking.
+- Hostname (SAN) verification is DISABLED by default; instead the client PINS the certificate: the agent must present a cert byte-identical to one in your `--tls-ca` file (expiry is ignored in this mode — you pinned that exact cert). Use `--verify-hostname` to switch to strict chain + SAN validation instead.
 - You can run multiple clients with different cert paths by passing --tls-ca per invocation.
 
 ---

scripts/install.sh

@@ -0,0 +1,246 @@
+#!/usr/bin/env bash
+# Build socktop + socktop_agent from source and install them.
+#
+# Works on Linux (x86_64, arm64/armv7, riscv64) and macOS. Handles fresh
+# installs and upgrades; if a systemd socktop-agent service is present, its
+# binary is replaced in place and the service restarted.
+#
+#   ./scripts/install.sh                     # build HEAD of the repo you're in
+#   ./scripts/install.sh --ref v1.60.0       # build a tag/branch (clones if needed)
+#   ./scripts/install.sh --ref master           # or any branch
+#   ./scripts/install.sh --prefix ~/.local/bin --no-service
+#
+set -euo pipefail
+
+REPO_URL="https://github.com/jasonwitty/socktop.git"
+REF=""
+PREFIX=""
+NO_SERVICE=0
+SRC_DIR="${SOCKTOP_SRC_DIR:-$HOME/.cache/socktop-src}"
+
+while [ $# -gt 0 ]; do
+  case "$1" in
+    --ref)       REF="$2"; shift 2 ;;
+    --prefix)    PREFIX="$2"; shift 2 ;;
+    --no-service) NO_SERVICE=1; shift ;;
+    -h|--help)   grep '^#' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
+    *) echo "unknown argument: $1" >&2; exit 2 ;;
+  esac
+done
+
+say()  { printf '\033[1;36m==>\033[0m %s\n' "$*"; }
+warn() { printf '\033[1;33mwarn:\033[0m %s\n' "$*" >&2; }
+die()  { printf '\033[1;31merror:\033[0m %s\n' "$*" >&2; exit 1; }
+
+# The entire remainder runs inside main(), invoked on the LAST line. This
+# makes the script safe against being MODIFIED WHILE RUNNING: when executed
+# from the clone it manages, the git checkout below replaces this very file,
+# and bash reads scripts lazily by byte offset — without this wrapper it
+# resumes parsing the NEW file at the OLD offset and executes an arbitrary
+# tail of it (observed: the fresh-service path ran on a host whose unit
+# already existed). With main(), the whole script is parsed before any of
+# it executes.
+main() {
+
+OS="$(uname -s)"
+ARCH="$(uname -m)"
+
+# ---------- toolchain ----------
+command -v git >/dev/null || die "git is required"
+if ! command -v cargo >/dev/null; then
+  # rustup may be installed but not on PATH in this shell
+  [ -f "$HOME/.cargo/env" ] && . "$HOME/.cargo/env"
+fi
+if ! command -v cargo >/dev/null; then
+  say "Rust toolchain not found — installing via rustup (stable, default profile)"
+  curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal
+  . "$HOME/.cargo/env"
+fi
+command -v cc >/dev/null || warn "no C compiler found (apt: build-essential / brew: xcode-select --install) — the build may fail"
+case "$ARCH" in
+  riscv64*)
+    # protoc-bin-vendored ships no riscv64 binary; the build falls back to
+    # the system protoc (see build.rs).
+    command -v protoc >/dev/null || die "riscv64 needs a system protoc: sudo apt install protobuf-compiler"
+    ;;
+esac
+
+# ---------- source ----------
+# If run from inside a socktop checkout and no --ref given, build that tree
+# as-is (whatever is checked out, including local changes).
+if [ -z "$REF" ] && git rev-parse --show-toplevel >/dev/null 2>&1 \
+   && grep -qs '^name = "socktop"' "$(git rev-parse --show-toplevel)/socktop/Cargo.toml" 2>/dev/null; then
+  SRC_DIR="$(git rev-parse --show-toplevel)"
+  say "Building the current checkout: $SRC_DIR ($(git -C "$SRC_DIR" describe --always --dirty 2>/dev/null))"
+else
+  REF="${REF:-master}"
+  if [ ! -d "$SRC_DIR/.git" ]; then
+    say "Cloning $REPO_URL -> $SRC_DIR"
+    git clone "$REPO_URL" "$SRC_DIR"
+  fi
+  say "Checking out $REF"
+  git -C "$SRC_DIR" fetch --tags origin
+  git -C "$SRC_DIR" checkout -q "$REF"
+  # fast-forward when REF is a branch
+  git -C "$SRC_DIR" merge --ff-only "origin/$REF" >/dev/null 2>&1 || true
+fi
+
+# ---------- build ----------
+say "Building release binaries (this can take a while on SBCs)"
+( cd "$SRC_DIR" && cargo build --release -p socktop -p socktop_agent )
+CLIENT="$SRC_DIR/target/release/socktop"
+AGENT="$SRC_DIR/target/release/socktop_agent"
+
+# ---------- install ----------
+if [ -z "$PREFIX" ]; then
+  PREFIX="/usr/local/bin"
+fi
+SUDO=""
+if [ ! -w "$PREFIX" ]; then
+  if command -v sudo >/dev/null; then SUDO="sudo"; else
+    PREFIX="$HOME/.local/bin"; mkdir -p "$PREFIX"
+    warn "no sudo — installing to $PREFIX (ensure it is on your PATH)"
+  fi
+fi
+say "Installing to $PREFIX"
+$SUDO install -m 755 "$CLIENT" "$PREFIX/socktop"
+$SUDO install -m 755 "$AGENT" "$PREFIX/socktop_agent"
+
+# Update every other copy on PATH as well. A stale `cargo install` in
+# ~/.cargo/bin would otherwise SHADOW the fresh binary (~/.cargo/bin
+# usually precedes /usr/local/bin on PATH), leaving `socktop --version`
+# stuck on the old release after a "successful" install.
+update_path_copies() {
+  local name="$1" src="$2" copy dir
+  # type -ap lists every match on PATH (bash builtin, symlinks not resolved)
+  for copy in $(type -ap "$name" | sort -u); do
+    [ "$copy" = "$PREFIX/$name" ] && continue
+    dir="$(dirname "$copy")"
+    say "Updating additional copy on PATH: $copy"
+    if [ -w "$copy" ] || [ -w "$dir" ]; then
+      install -m 755 "$src" "$copy"
+    else
+      # Non-fatal: an un-updatable extra copy shouldn't kill the install,
+      # but the user must know it may shadow the fresh binary.
+      $SUDO install -m 755 "$src" "$copy"         || warn "could not update $copy — it may shadow $PREFIX/$name"
+    fi
+  done
+}
+update_path_copies socktop "$CLIENT"
+update_path_copies socktop_agent "$AGENT"
+
+# ---------- systemd service (Linux only) ----------
+# System-level operations (unit files, users, service control) need root no
+# matter where the binaries were installed — decide independently of PREFIX.
+SYS_SUDO=""
+if [ "$(id -u)" -ne 0 ]; then
+  if command -v sudo >/dev/null; then SYS_SUDO="sudo"; else SYS_SUDO="__none__"; fi
+fi
+if [ "$SYS_SUDO" = "__none__" ] && [ "$NO_SERVICE" -eq 0 ]; then
+  warn "no sudo available — skipping systemd service management"
+  NO_SERVICE=1
+fi
+if [ "$OS" = "Linux" ] && [ "$NO_SERVICE" -eq 0 ] && command -v systemctl >/dev/null; then
+  if systemctl cat socktop-agent.service >/dev/null 2>&1; then
+    # UPGRADE: the unit file is the operator's (SSL, tokens, ports may be
+    # configured there) — never overwrite it. Only the binary it points at
+    # is replaced, then the service is restarted.
+    say "Existing socktop-agent.service found — preserving unit file, refreshing binary"
+    UNIT_BIN="$(systemctl show -p ExecStart socktop-agent.service 2>/dev/null \
+                | sed -n 's/.*path=\([^ ;]*\).*/\1/p' | head -1)"
+    if [ -n "$UNIT_BIN" ] && [ "$UNIT_BIN" != "$PREFIX/socktop_agent" ]; then
+      $SYS_SUDO systemctl stop socktop-agent.service
+      $SYS_SUDO install -m 755 "$AGENT" "$UNIT_BIN"
+      $SYS_SUDO systemctl start socktop-agent.service
+    else
+      $SYS_SUDO systemctl restart socktop-agent.service
+    fi
+  else
+    # FRESH INSTALL: unit + the system user it runs as + its state dir,
+    # then enable and start. Mirrors the deb package's postinst and
+    # https://www.socktop.io/assets/docs/installation/agent-service.html
+    say "No socktop-agent.service found — installing and enabling it"
+
+    if ! getent group socktop >/dev/null; then
+      $SYS_SUDO groupadd --system socktop
+    fi
+    if ! getent passwd socktop >/dev/null; then
+      NOLOGIN="$(command -v nologin || echo /usr/sbin/nologin)"
+      $SYS_SUDO useradd --system -g socktop -d /var/lib/socktop -M -s "$NOLOGIN" socktop
+    fi
+    $SYS_SUDO mkdir -p /var/lib/socktop
+    $SYS_SUDO chown socktop:socktop /var/lib/socktop
+    $SYS_SUDO chmod 755 /var/lib/socktop
+
+    UNIT_TMP="$(mktemp)"
+    if [ -f "$SRC_DIR/docs/socktop-agent.service" ]; then
+      cp "$SRC_DIR/docs/socktop-agent.service" "$UNIT_TMP"
+    else
+      # Fallback for refs that predate docs/socktop-agent.service
+      cat > "$UNIT_TMP" <<'UNIT'
+[Unit]
+Description=Socktop agent
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/socktop_agent --port 3000
+Environment=RUST_LOG=info
+# Optional auth:
+# Environment=SOCKTOP_TOKEN=changeme
+# TLS (self-signed cert on first run, default port 8443):
+# Environment=SOCKTOP_ENABLE_SSL=1
+Restart=on-failure
+User=socktop
+Group=socktop
+NoNewPrivileges=true
+
+[Install]
+WantedBy=multi-user.target
+UNIT
+    fi
+    # Pick the agent port: 3000 by default, but NEVER bind onto a port that
+    # something else already holds (e.g. Gitea/Umami and friends love 3000)
+    # — that puts the fresh service straight into a crash-restart loop.
+    AGENT_PORT=""
+    for p in 3000 3001 3010 3231 3232; do
+      if ! ss -tln 2>/dev/null | awk '{print $4}' | grep -q ":${p}\$"; then
+        AGENT_PORT="$p"
+        break
+      fi
+    done
+    if [ -z "$AGENT_PORT" ]; then
+      AGENT_PORT=3000
+      warn "no free port among the defaults — using 3000; edit the unit if the service fails to start"
+    elif [ "$AGENT_PORT" != "3000" ]; then
+      warn "port 3000 is already in use by another service — configuring the agent on port $AGENT_PORT"
+    fi
+
+    # Point ExecStart at wherever this run installed the agent, on the chosen port.
+    sed -i.bak -e "s|^ExecStart=[^ ]*socktop_agent|ExecStart=$PREFIX/socktop_agent|" \
+               -e "s|--port [0-9]*|--port $AGENT_PORT|" "$UNIT_TMP"
+    rm -f "$UNIT_TMP.bak"
+
+    $SYS_SUDO install -o root -g root -m 0644 "$UNIT_TMP" /etc/systemd/system/socktop-agent.service
+    rm -f "$UNIT_TMP"
+    $SYS_SUDO systemctl daemon-reload
+    $SYS_SUDO systemctl enable --now socktop-agent.service
+    say "Service installed — agent URL: ws://$(hostname):$AGENT_PORT/ws"
+    say "To enable TLS or a token, edit /etc/systemd/system/socktop-agent.service, then: sudo systemctl daemon-reload && sudo systemctl restart socktop-agent"
+  fi
+  sleep 1
+  systemctl --no-pager -l status socktop-agent.service | head -5 || true
+fi
+
+say "Installed:"
+"$PREFIX/socktop" --version
+"$PREFIX/socktop_agent" --version
+say "Active on PATH: $(type -p socktop || true) / $(type -p socktop_agent || true)"
+socktop --version
+
+}
+
+# exit in the same parse unit as the call: after main returns, bash must not
+# read another byte from this (possibly replaced) file.
+main "$@"; exit $?

scripts/sync-gitea.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Sync this repo to the 'gitea' remote as a mirror.
+# - Mirrors ALL refs (branches, tags) and prunes removed ones.
+# - This makes the Gitea repo match GitHub exactly.
+
+if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+  echo "Error: not inside a git repo" >&2
+  exit 1
+fi
+
+if ! git remote get-url gitea >/dev/null 2>&1; then
+  echo "Missing 'gitea' remote. Add it with:" >&2
+  echo "  git remote add gitea https://gt.wittyoneoff.com/jason/socktop.git" >&2
+  exit 1
+fi
+
+echo "Fetching from origin (pruning)..."
+git fetch origin --prune --tags
+
+echo "Pushing mirror to gitea..."
+git push gitea --mirror
+
+echo "Done: Gitea should now match origin (GitHub)."
+

socktop/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "socktop"
-version = "1.50.0"
+version = "1.60.0"
 authors = ["Jason Witty <jasonpwitty+socktop@proton.me>"]
 description = "Remote system monitor over WebSocket, TUI like top"
 edition = "2024"
@@ -11,7 +11,7 @@ repository = "https://github.com/jasonwitty/socktop"
 
 [dependencies]
 # socktop connector for agent communication
-socktop_connector = "1.50.0"
+socktop_connector = { version = "1.60.0", path = "../socktop_connector" }
 
 tokio = { workspace = true }
 futures-util = { workspace = true }
@@ -20,9 +20,12 @@ serde_json = { workspace = true }
 url = { workspace = true }
 ratatui = { workspace = true }
 crossterm = { workspace = true }
+unicode-width = { workspace = true }
 anyhow = { workspace = true }
-dirs-next = { workspace = true }
+# Local process signalling only (src/proc_kill.rs). The TUI never gathers its
+# own metrics — everything on screen comes from the agent over the connector.
 sysinfo = { workspace = true }
+dirs-next = { workspace = true }
 
 [dev-dependencies]
 assert_cmd = "2.0"

socktop/src/history.rs

@@ -2,16 +2,25 @@
 
 use std::collections::VecDeque;
 
-pub fn push_capped<T>(dq: &mut VecDeque<T>, v: T, cap: usize) {
-    if dq.len() == cap {
-        dq.pop_front();
-    }
+/// Push a value into a capped deque. Returns the evicted front element if any.
+/// Callers maintaining a running sum can use this to update the sum without
+/// re-iterating the whole deque.
+pub fn push_capped<T>(dq: &mut VecDeque<T>, v: T, cap: usize) -> Option<T> {
+    let evicted = if dq.len() == cap {
+        dq.pop_front()
+    } else {
+        None
+    };
     dq.push_back(v);
+    evicted
 }
 
-// Keeps a history deque per core with a fixed capacity
+// Keeps a history deque per core with a fixed capacity.
+// Storage is u64 so sparkline rendering can hand the slice directly to
+// ratatui's `Sparkline::data` (which takes `&[u64]`) without per-frame
+// allocation or widening conversion.
 pub struct PerCoreHistory {
-    pub deques: Vec<VecDeque<u16>>,
+    pub deques: Vec<VecDeque<u64>>,
     cap: usize,
 }
 
@@ -35,7 +44,7 @@ impl PerCoreHistory {
     pub fn push_samples(&mut self, samples: &[f32]) {
         self.ensure_cores(samples.len());
         for (i, v) in samples.iter().enumerate() {
-            let val = v.clamp(0.0, 100.0).round() as u16;
+            let val = v.clamp(0.0, 100.0).round() as u64;
             push_capped(&mut self.deques[i], val, self.cap);
         }
     }

socktop/src/local.rs

@@ -0,0 +1,85 @@
+//! Detection of whether the connected agent is running on this same machine.
+//!
+//! Process-kill is only offered for *local* agents. The reasoning is a
+//! security one: the PIDs shown in the UI are reported by the agent, and when
+//! the user asks to kill one, socktop sends the signal with its OWN local OS
+//! privileges (a direct syscall — never over the network; see [`crate::proc_kill`]).
+//! A PID is therefore only meaningful — and only safe to act on — when the
+//! agent lives on this machine. If we acted on a remote agent's PIDs we would
+//! be signalling whatever unrelated *local* process happened to share that
+//! number.
+//!
+//! An address is considered local when it is loopback, or when we can bind an
+//! ephemeral socket to it: a bind only succeeds for an address assigned to one
+//! of this host's own network interfaces, so it also covers the case of an
+//! agent reached over this machine's LAN IP. Detection fails closed — any
+//! parse/resolution failure, or any resolved address that is not local,
+//! disables the feature.
+
+use std::net::{IpAddr, ToSocketAddrs, UdpSocket};
+
+/// Returns true only if the agent reached at `ws_url` is on this machine.
+pub fn agent_is_local(ws_url: &str) -> bool {
+    let Ok(parsed) = url::Url::parse(ws_url) else {
+        return false;
+    };
+    match parsed.host() {
+        // IP literals can be checked directly without any name resolution.
+        Some(url::Host::Ipv4(ip)) => ip_is_local(IpAddr::V4(ip)),
+        Some(url::Host::Ipv6(ip)) => ip_is_local(IpAddr::V6(ip)),
+        // A hostname (e.g. "localhost", or a LAN name) must resolve, and every
+        // address it resolves to must be local. ws=80, wss=443 are the known
+        // default ports; an explicit port in the URL is honored.
+        Some(url::Host::Domain(domain)) => {
+            let port = parsed.port_or_known_default().unwrap_or(0);
+            match (domain, port).to_socket_addrs() {
+                Ok(addrs) => {
+                    let mut saw_any = false;
+                    for addr in addrs {
+                        saw_any = true;
+                        if !ip_is_local(addr.ip()) {
+                            return false;
+                        }
+                    }
+                    saw_any
+                }
+                Err(_) => false,
+            }
+        }
+        None => false,
+    }
+}
+
+/// An address is local if it is loopback, or if we can bind an ephemeral
+/// socket to it (only possible for an address on one of our own interfaces).
+/// Port 0 requests an ephemeral port and sends no traffic.
+fn ip_is_local(ip: IpAddr) -> bool {
+    ip.is_loopback() || UdpSocket::bind((ip, 0)).is_ok()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::agent_is_local;
+
+    #[test]
+    fn loopback_hosts_are_local() {
+        assert!(agent_is_local("ws://127.0.0.1:3000/ws"));
+        assert!(agent_is_local("ws://localhost:3000/ws"));
+        assert!(agent_is_local("ws://[::1]:3000/ws"));
+        assert!(agent_is_local("wss://127.0.0.1/ws"));
+    }
+
+    #[test]
+    fn public_addresses_are_not_local() {
+        // 8.8.8.8 is not assigned to any local interface.
+        assert!(!agent_is_local("ws://8.8.8.8:3000/ws"));
+        // Documentation-range address, guaranteed not bound locally.
+        assert!(!agent_is_local("ws://203.0.113.1:3000/ws"));
+    }
+
+    #[test]
+    fn garbage_fails_closed() {
+        assert!(!agent_is_local("not a url"));
+        assert!(!agent_is_local(""));
+    }
+}

socktop/src/main.rs

@@ -2,6 +2,8 @@
 
 mod app;
 mod history;
+mod local;
+mod proc_kill;
 mod profiles;
 mod retry;
 mod types;
@@ -22,6 +24,7 @@ pub(crate) struct ParsedArgs {
     metrics_interval_ms: Option<u64>,
     processes_interval_ms: Option<u64>,
     verify_hostname: bool,
+    compact: bool,
 }
 
 pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<ParsedArgs, String> {
@@ -36,11 +39,12 @@ pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<Pars
     let mut metrics_interval_ms: Option<u64> = None;
     let mut processes_interval_ms: Option<u64> = None;
     let mut verify_hostname = false;
+    let mut compact = false;
     while let Some(arg) = it.next() {
         match arg.as_str() {
             "-h" | "--help" => {
                 return Err(format!(
-                    "Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [--metrics-interval-ms N] [--processes-interval-ms N] [ws://HOST:PORT/ws]\n"
+                    "Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [--compact] [--metrics-interval-ms N] [--processes-interval-ms N] [ws://HOST:PORT/ws]\n"
                 ));
             }
             "--tls-ca" | "-t" => {
@@ -61,6 +65,11 @@ pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<Pars
             "--demo" => {
                 demo = true;
             }
+            "--compact" => {
+                // Force the small-window layout at any terminal size. Without it the
+                // layout switches on its own once the window gets too short.
+                compact = true;
+            }
             "--dry-run" => {
                 // intentionally undocumented
                 dry_run = true;
@@ -100,7 +109,7 @@ pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<Pars
                     url = Some(arg);
                 } else {
                     return Err(format!(
-                        "Unexpected argument. Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [ws://HOST:PORT/ws]"
+                        "Unexpected argument. Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [--compact] [ws://HOST:PORT/ws]"
                     ));
                 }
             }
@@ -116,6 +125,7 @@ pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<Pars
         metrics_interval_ms,
         processes_interval_ms,
         verify_hostname,
+        compact,
     })
 }
 
@@ -136,7 +146,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     }
 
     if parsed.demo || matches!(parsed.profile.as_deref(), Some("demo")) {
-        return run_demo_mode(parsed.tls_ca.as_deref()).await;
+        return run_demo_mode(parsed.tls_ca.as_deref(), parsed.compact).await;
     }
 
     let profiles_file = load_profiles();
@@ -241,7 +251,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                     if (1..=names.len()).contains(&idx) {
                         let name = &names[idx - 1];
                         if name == "demo" {
-                            return run_demo_mode(parsed.tls_ca.as_deref()).await;
+                            return run_demo_mode(parsed.tls_ca.as_deref(), parsed.compact).await;
                         }
                         if let Some(entry) = profiles_mut.profiles.get(name) {
                             (
@@ -301,7 +311,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                 );
                 eprintln!("If you don't have an agent running, you can try the demo mode.");
                 if prompt_yes_no("Would you like to start the demo mode now? [Y/n]: ") {
-                    return run_demo_mode(parsed.tls_ca.as_deref()).await;
+                    return run_demo_mode(parsed.tls_ca.as_deref(), parsed.compact).await;
                 } else {
                     eprintln!("Aborting. You can run 'socktop --help' for usage information.");
                     return Ok(());
@@ -313,9 +323,15 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     let is_tls = url.starts_with("wss://");
     let has_token = url.contains("token=");
+    // Only enable local process-kill when the agent is verified to be on this
+    // machine; otherwise on-screen PIDs refer to a remote host and acting on
+    // them locally would signal the wrong process. See local::agent_is_local.
+    let is_local = local::agent_is_local(&url);
     let mut app = App::new()
         .with_intervals(metrics_interval_ms, processes_interval_ms)
-        .with_status(is_tls, has_token);
+        .with_status(is_tls, has_token)
+        .with_compact(parsed.compact)
+        .with_local(is_local);
     if parsed.dry_run {
         return Ok(());
     }
@@ -379,11 +395,28 @@ fn gather_intervals(
 }
 
 // Demo mode implementation
-async fn run_demo_mode(_tls_ca: Option<&str>) -> Result<(), Box<dyn std::error::Error>> {
+async fn run_demo_mode(
+    _tls_ca: Option<&str>,
+    compact: bool,
+) -> Result<(), Box<dyn std::error::Error>> {
     let port = 3231;
     let url = format!("ws://127.0.0.1:{port}/ws");
-    let child = spawn_demo_agent(port)?;
-    let mut app = App::new();
+    let child = match spawn_demo_agent(port) {
+        Ok(child) => child,
+        // The agent ships as its own binary, so a missing one is a setup problem,
+        // not a crash: tell the user how to fix it instead of dumping an io error.
+        Err(e @ DemoAgentError::NotFound(_)) => {
+            eprintln!("{e}");
+            return Ok(());
+        }
+        Err(e) => return Err(e.into()),
+    };
+    // Demo mode runs the real agent on loopback, so its PIDs are real local
+    // processes — enable the local process-kill feature, gated the same way as
+    // the normal connect path (loopback resolves local).
+    let mut app = App::new()
+        .with_compact(compact)
+        .with_local(local::agent_is_local(&url));
     // Demo mode connects to localhost, so disable hostname verification
     tokio::select! { res=app.run(&url,None,false)=>{ drop(child); res } _=tokio::signal::ctrl_c()=>{ drop(child); Ok(()) } }
 }
@@ -399,9 +432,50 @@ impl Drop for DemoGuard {
         eprintln!("Stopped demo agent on port {}", self.port);
     }
 }
-fn spawn_demo_agent(port: u16) -> Result<DemoGuard, Box<dyn std::error::Error>> {
+#[derive(Debug)]
+enum DemoAgentError {
+    /// The socktop_agent executable could not be located.
+    NotFound(std::path::PathBuf),
+    Io(std::io::Error),
+}
+
+impl std::fmt::Display for DemoAgentError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::NotFound(candidate) => write!(
+                f,
+                "Could not start demo mode: '{}' was not found{}.\n\
+                 \n\
+                 Demo mode runs a local agent, which is shipped as a separate binary\n\
+                 and is not installed alongside the socktop TUI. Install it with:\n\
+                 \n    cargo install socktop_agent\n\n\
+                 then run socktop again. See {} for other install options.",
+                candidate.display(),
+                // A bare file name means find_agent_executable() fell back to a PATH lookup.
+                if candidate.parent().is_none_or(|p| p.as_os_str().is_empty()) {
+                    " on your PATH"
+                } else {
+                    ""
+                },
+                env!("CARGO_PKG_HOMEPAGE"),
+            ),
+            Self::Io(e) => write!(f, "Could not start demo mode: {e}"),
+        }
+    }
+}
+
+impl std::error::Error for DemoAgentError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            Self::NotFound(_) => None,
+            Self::Io(e) => Some(e),
+        }
+    }
+}
+
+fn spawn_demo_agent(port: u16) -> Result<DemoGuard, DemoAgentError> {
     let candidate = find_agent_executable();
-    let mut cmd = std::process::Command::new(candidate);
+    let mut cmd = std::process::Command::new(&candidate);
     cmd.arg("--port").arg(port.to_string());
     cmd.env("SOCKTOP_ENABLE_SSL", "0");
 
@@ -409,7 +483,10 @@ fn spawn_demo_agent(port: u16) -> Result<DemoGuard, Box<dyn std::error::Error>>
     //cmd.env("SOCKTOP_AGENT_GPU", "0");
     //cmd.env("SOCKTOP_AGENT_TEMP", "0");
 
-    let child = cmd.spawn()?;
+    let child = cmd.spawn().map_err(|e| match e.kind() {
+        std::io::ErrorKind::NotFound => DemoAgentError::NotFound(candidate),
+        _ => DemoAgentError::Io(e),
+    })?;
     std::thread::sleep(std::time::Duration::from_millis(300));
     Ok(DemoGuard {
         port,

socktop/src/proc_kill.rs

@@ -0,0 +1,181 @@
+//! Local process termination.
+//!
+//! Signals are sent by socktop itself, using this process's own OS privileges,
+//! via a direct `sysinfo` call. Nothing is transmitted to the agent — the
+//! agent and connector have no kill capability at all. This code path is only
+//! reachable once the agent has been verified to be local (see
+//! [`crate::local`]), which guarantees the PID refers to a process on this
+//! machine.
+
+use sysinfo::{ProcessRefreshKind, ProcessesToUpdate, Signal, System};
+
+/// The signals socktop can send. Deliberately limited to the two btop-style
+/// primaries; no arbitrary-signal chooser.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum KillSignal {
+    /// SIGTERM — polite request to terminate.
+    Term,
+    /// SIGKILL — forceful, cannot be caught.
+    Kill,
+}
+
+impl KillSignal {
+    fn as_sysinfo(self) -> Signal {
+        match self {
+            KillSignal::Term => Signal::Term,
+            KillSignal::Kill => Signal::Kill,
+        }
+    }
+
+    /// Human-facing label for confirmation/result messages.
+    pub fn label(self) -> &'static str {
+        match self {
+            KillSignal::Term => "SIGTERM",
+            KillSignal::Kill => "SIGKILL",
+        }
+    }
+}
+
+/// Is `pid` still a live local process?
+///
+/// A zombie counts as gone: after a kill the entry can linger until the parent
+/// reaps it, and showing a row for a process that no longer runs is exactly the
+/// staleness this check exists to avoid.
+pub fn process_exists(pid: u32) -> bool {
+    let spid = sysinfo::Pid::from_u32(pid);
+    let mut sys = System::new();
+    sys.refresh_processes_specifics(
+        ProcessesToUpdate::Some(&[spid]),
+        false,
+        ProcessRefreshKind::nothing(),
+    );
+    match sys.process(spid) {
+        Some(p) => p.status() != sysinfo::ProcessStatus::Zombie,
+        None => false,
+    }
+}
+
+/// Send `signal` to local process `pid`. Returns `Ok(())` on success, or an
+/// `Err` with a human-readable reason (process gone, PID reused, permission
+/// denied, signal unsupported on this platform).
+///
+/// `expected_name`, when given, is compared against the process that owns the
+/// PID **right now**: the PID came from an agent snapshot and the confirmation
+/// dialog can sit open indefinitely, so by signal time the kernel may have
+/// recycled the number for an unrelated process. Both names come from the
+/// same sysinfo source, so a live, unchanged target compares equal.
+pub fn kill_local_process(
+    pid: u32,
+    expected_name: Option<&str>,
+    signal: KillSignal,
+) -> Result<(), String> {
+    let spid = sysinfo::Pid::from_u32(pid);
+
+    // Refresh just this one PID — we don't need a full process scan to signal it.
+    let mut sys = System::new();
+    sys.refresh_processes_specifics(
+        ProcessesToUpdate::Some(&[spid]),
+        false,
+        ProcessRefreshKind::nothing(),
+    );
+
+    let Some(proc_) = sys.process(spid) else {
+        return Err(format!("Process {pid} no longer exists"));
+    };
+
+    if let Some(expected) = expected_name {
+        let current = proc_.name().to_string_lossy();
+        if current != expected {
+            return Err(format!(
+                "PID {pid} now belongs to \"{current}\", not \"{expected}\" — \
+                 not signalling. Reselect the process and try again."
+            ));
+        }
+    }
+
+    match proc_.kill_with(signal.as_sysinfo()) {
+        Some(true) => Ok(()),
+        Some(false) => Err(format!(
+            "Could not send {} to PID {pid} (permission denied?)",
+            signal.label()
+        )),
+        None => Err(format!(
+            "{} is not supported on this platform",
+            signal.label()
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::process::Command;
+    use std::time::{Duration, Instant};
+
+    /// The path that matters: a real, live, local process must actually receive
+    /// the signal. Exercises the `refresh_processes_specifics` lookup as well —
+    /// if that call does not populate the process map, `sys.process()` returns
+    /// None and a live PID is reported as "no longer exists".
+    #[test]
+    fn signals_a_real_child_process() {
+        let mut child = Command::new("sleep")
+            .arg("30")
+            .spawn()
+            .expect("spawn sleep for the test");
+        let pid = child.id();
+
+        let result = kill_local_process(pid, Some("sleep"), KillSignal::Term);
+
+        // Reap on every path before asserting, so a failing assert cannot leak a
+        // 30s sleep and cannot trip clippy's zombie_processes lint.
+        let deadline = Instant::now() + Duration::from_secs(5);
+        let mut exited = false;
+        while Instant::now() < deadline {
+            if matches!(child.try_wait(), Ok(Some(_))) {
+                exited = true;
+                break;
+            }
+            std::thread::sleep(Duration::from_millis(20));
+        }
+        if !exited {
+            let _ = child.kill();
+        }
+        let _ = child.wait();
+
+        assert!(result.is_ok(), "kill_local_process returned {result:?}");
+        assert!(
+            exited,
+            "SIGTERM was reported sent but the child never exited"
+        );
+    }
+
+    /// The reuse guard: a live PID whose owner does not match the name the
+    /// user confirmed must NOT be signalled. This also proves the name is
+    /// populated under ProcessRefreshKind::nothing() — if it weren't, the
+    /// matching-name test above would fail instead.
+    #[test]
+    fn refuses_a_pid_owned_by_a_different_process() {
+        let mut child = Command::new("sleep")
+            .arg("30")
+            .spawn()
+            .expect("spawn sleep");
+        let pid = child.id();
+
+        let result = kill_local_process(pid, Some("firefox"), KillSignal::Term);
+
+        let _ = child.kill();
+        let _ = child.wait();
+
+        let err = result.expect_err("signalled a process under the wrong name");
+        assert!(err.contains("firefox") && err.contains("sleep"), "{err}");
+    }
+
+    #[test]
+    fn reports_a_pid_that_is_gone() {
+        let mut child = Command::new("true").spawn().expect("spawn true");
+        let pid = child.id();
+        child.wait().expect("reap");
+        // The PID is now free; signalling it must fail cleanly, not panic.
+        assert!(kill_local_process(pid, None, KillSignal::Term).is_err());
+    }
+}

socktop/src/ui/cpu.rs

@@ -7,11 +7,17 @@ use ratatui::style::{Color, Style};
 use ratatui::{
     layout::{Constraint, Direction, Layout, Rect},
     text::{Line, Span},
-    widgets::{Block, Borders, Paragraph, Sparkline},
+    widgets::{
+        Block, Borders, Paragraph, Scrollbar, ScrollbarOrientation, ScrollbarState, Sparkline,
+    },
 };
 
 use crate::history::PerCoreHistory;
 use crate::types::Metrics;
+use crate::ui::fit::{cols, pick_pair};
+
+/// Columns kept clear between the CPU title and the temperature readout.
+const TITLE_GAP: u16 = 2;
 
 /// State for dragging the scrollbar thumb
 #[derive(Clone, Copy, Debug, Default)]
@@ -133,11 +139,9 @@ pub fn per_core_handle_scrollbar_mouse(
     }
     let thumb_len = (track * view).div_ceil(total).max(1).min(track);
     let top_for_offset = |off: usize| -> usize {
-        if max_off == 0 {
-            0
-        } else {
-            ((track - thumb_len) * off + max_off / 2) / max_off
-        }
+        ((track - thumb_len) * off + max_off / 2)
+            .checked_div(max_off)
+            .unwrap_or(0)
     };
     let thumb_top = top_for_offset(offset);
 
@@ -190,11 +194,9 @@ pub fn per_core_handle_scrollbar_mouse(
                 // Inverse mapping top -> offset
                 if track > thumb_len {
                     let denom = track - thumb_len;
-                    offset = if max_off == 0 {
-                        0
-                    } else {
-                        (new_top * max_off + denom / 2) / denom
-                    };
+                    offset = (new_top * max_off + denom / 2)
+                        .checked_div(denom)
+                        .unwrap_or(0);
                 } else {
                     offset = 0;
                 }
@@ -234,62 +236,51 @@ pub fn per_core_clamp(scroll_offset: &mut usize, total_rows: usize, viewport_row
 }
 
 /// Draws the CPU average sparkline graph.
+///
+/// `hist_sum` is the running sum of `hist` maintained by the caller so we don't
+/// fold the (up to 600-element) deque on every frame.
 pub fn draw_cpu_avg_graph(
     f: &mut ratatui::Frame<'_>,
     area: Rect,
-    hist: &std::collections::VecDeque<u64>,
+    hist: &mut std::collections::VecDeque<u64>,
+    hist_sum: u64,
     m: Option<&Metrics>,
 ) {
-    // Calculate average CPU over the monitoring period
-    let avg_cpu = if !hist.is_empty() {
-        let sum: u64 = hist.iter().sum();
-        sum as f64 / hist.len() as f64
-    } else {
+    let avg_cpu = if hist.is_empty() {
         0.0
-    };
-
-    let title = if let Some(mm) = m {
-        format!("CPU (now: {:>5.1}% | avg: {:>5.1}%)", mm.cpu_total, avg_cpu)
     } else {
-        "CPU avg".into()
+        hist_sum as f64 / hist.len() as f64
     };
 
-    // Build the top-right info (CPU temp and polling intervals)
-    let top_right_info = if let Some(mm) = m {
-        mm.cpu_temp_c
-            .map(|t| {
-                let icon = if t < 50.0 {
-                    "😎"
-                } else if t < 85.0 {
-                    "⚠️"
-                } else {
-                    "🔥"
-                };
-                format!("CPU Temp: {t:.1}°C {icon}")
-            })
-            .unwrap_or_else(|| "CPU Temp: N/A".into())
-    } else {
-        String::new()
-    };
+    let (title, top_right_info) = cpu_title_for_width(
+        m.map(|mm| mm.cpu_total),
+        avg_cpu,
+        m.and_then(|mm| mm.cpu_temp_c),
+        area.width,
+    );
 
+    // Hand a slice directly to Sparkline. `make_contiguous` is amortized cheap
+    // for our usage pattern (cap'd 600-element ring updated at 2 Hz) and lets
+    // us skip the per-frame Vec allocation .collect() used to do.
     let max_points = area.width.saturating_sub(2) as usize;
     let start = hist.len().saturating_sub(max_points);
-    let data: Vec<u64> = hist.iter().skip(start).cloned().collect();
+    let slice = &hist.make_contiguous()[start..];
 
-    // Render the sparkline with title on left
     let spark = Sparkline::default()
         .block(Block::default().borders(Borders::ALL).title(title))
-        .data(&data)
+        .data(slice)
         .max(100)
         .style(Style::default().fg(Color::Cyan));
     f.render_widget(spark, area);
 
-    // Render the top-right info as text overlay in the top-right corner
+    // Temperature overlays the top border, right-aligned inside the corner. The title
+    // above is sized so the two cannot collide.
     if !top_right_info.is_empty() {
+        let w = cols(&top_right_info);
         let info_area = Rect {
-            x: area.x + area.width.saturating_sub(top_right_info.len() as u16 + 2),
+            x: area.x + area.width.saturating_sub(w + 1),
             y: area.y,
-            width: top_right_info.len() as u16 + 1,
+            width: w,
             height: 1,
         };
         let info_line = Line::from(Span::raw(top_right_info));
@@ -297,12 +288,73 @@ pub fn draw_cpu_avg_graph(
     }
 }
 
+/// Health glyph for a CPU temperature.
+fn temp_icon(t: f32) -> &'static str {
+    if t < 50.0 {
+        "😎"
+    } else if t < 85.0 {
+        "⚠️"
+    } else {
+        "🔥"
+    }
+}
+
+/// Chooses the CPU pane's title and its right-aligned temperature readout for a pane
+/// `width` columns wide.
+///
+/// Both are painted onto the pane's top border, so without a shared budget the
+/// temperature simply overwrites the tail of the title on a narrow pane. Detail is given
+/// up in this order: the `CPU Temp:` label, then the `now:`/`avg:` labels, then the
+/// average reading, then the decimal on the temperature, and only last the temperature
+/// itself — the readings are what the pane is for, but a thermal warning is worth more
+/// than a second decimal place.
+fn cpu_title_for_width(
+    cpu_now: Option<f32>,
+    avg_cpu: f64,
+    temp_c: Option<f32>,
+    width: u16,
+) -> (String, String) {
+    let Some(now) = cpu_now else {
+        return ("CPU avg".into(), String::new());
+    };
+
+    // Two borders, plus a column of breathing room at each end of the title.
+    let budget = width.saturating_sub(4);
+
+    let labelled = format!("CPU (now: {now:>5.1}% | avg: {avg_cpu:>5.1}%)");
+    let bare = format!("CPU ({now:.1}% | {avg_cpu:.1}%)");
+    let now_only = format!("CPU ({now:.1}%)");
+
+    let (temp_labelled, temp_plain, temp_coarse) = match temp_c {
+        Some(t) => {
+            let icon = temp_icon(t);
+            (
+                format!("CPU Temp: {t:.1}°C {icon}"),
+                format!("{t:.1}°C {icon}"),
+                format!("{t:.0}°C {icon}"),
+            )
+        }
+        None => ("CPU Temp: N/A".into(), "N/A".into(), "N/A".into()),
+    };
+
+    let ladder = [
+        (labelled.as_str(), temp_labelled.as_str()),
+        (labelled.as_str(), temp_plain.as_str()),
+        (bare.as_str(), temp_plain.as_str()),
+        (bare.as_str(), temp_coarse.as_str()),
+        (now_only.as_str(), temp_coarse.as_str()),
+        (now_only.as_str(), ""),
+    ];
+    let (title, temp) = pick_pair(budget, TITLE_GAP, &ladder);
+    (title.to_string(), temp.to_string())
+}
+
 /// Draws the per-core CPU bars with sparklines and trends.
 pub fn draw_per_core_bars(
     f: &mut ratatui::Frame<'_>,
     area: Rect,
     m: Option<&Metrics>,
-    per_core_hist: &PerCoreHistory,
+    per_core_hist: &mut PerCoreHistory,
     scroll_offset: usize,
 ) {
     f.render_widget(
@@ -347,7 +399,7 @@ pub fn draw_per_core_bars(
         let rect = vchunks[i];
         let hchunks = Layout::default()
             .direction(Direction::Horizontal)
-            .constraints([Constraint::Min(6), Constraint::Length(12)])
+            .constraints([Constraint::Min(6), Constraint::Length(13)])
             .split(rect);
 
         let curr = mm.cpu_per_core[idx].clamp(0.0, 100.0);
@@ -358,12 +410,17 @@ pub fn draw_per_core_bars(
             .map(|v| v as f32)
             .unwrap_or(curr);
 
+        // Trend indicator. Various Unicode glyphs we tried for the "flat"
+        // trend (╌, ·) substituted as a hyphen on terminals with narrow font
+        // coverage; combined with the next column being `100.0` they read as
+        // `cpu0 -100.0%`, a nonsensical negative percent. Use a literal space
+        // for the flat case — no character, no fallback, no confusion.
         let trend = if curr > older + 0.2 {
             "↑"
         } else if curr + 0.2 < older {
             "↓"
         } else {
-            "╌"
+            " "
         };
 
         let fg = match curr {
@@ -372,24 +429,24 @@ pub fn draw_per_core_bars(
             _ => Color::Red,
         };
 
-        let hist: Vec<u64> = per_core_hist
-            .deques
-            .get(idx)
-            .map(|d| {
-                let max_points = hchunks[0].width as usize;
-                let start = d.len().saturating_sub(max_points);
-                d.iter().skip(start).map(|&v| v as u64).collect()
-            })
-            .unwrap_or_default();
+        // Borrow the per-core deque mutably so we can hand a contiguous slice
+        // to Sparkline without allocating a fresh Vec each frame.
+        if let Some(d) = per_core_hist.deques.get_mut(idx) {
+            let max_points = hchunks[0].width as usize;
+            let start = d.len().saturating_sub(max_points);
+            let slice = &d.make_contiguous()[start..];
+            let spark = Sparkline::default()
+                .data(slice)
+                .max(100)
+                .style(Style::default().fg(fg));
+            f.render_widget(spark, hchunks[0]);
+        }
 
-        let spark = Sparkline::default()
-            .data(&hist)
-            .max(100)
-            .style(Style::default().fg(fg));
-
-        f.render_widget(spark, hchunks[0]);
-
-        let label = format!("cpu{idx:<2}{trend}{curr:>5.1}%");
+        // Hard space between the trend mark and the number — even if the
+        // arrow glyphs (↑/↓) fall back to ASCII on a terminal that lacks
+        // them, this space prevents the trend mark from visually joining
+        // `100.0` to look like a negative value.
+        let label = format!("cpu{idx:<2}{trend} {curr:>5.1}%");
         let line = Line::from(Span::styled(
             label,
             Style::default().fg(fg).add_modifier(Modifier::BOLD),
@@ -397,38 +454,225 @@ pub fn draw_per_core_bars(
         f.render_widget(Paragraph::new(line).right_aligned(), hchunks[1]);
     }
 
-    // Custom 1-col scrollbar with arrows, track, and exact mapping
+    // 1-col scrollbar (ratatui built-in widget). Skips drawing when the
+    // content fits in the viewport, matching the previous behaviour.
     let scroll_area = Rect {
         x: inner.x + inner.width.saturating_sub(1),
         y: inner.y,
         width: 1,
         height: inner.height,
     };
-    if scroll_area.height >= 3 {
-        let track = (scroll_area.height - 2) as usize;
-        let total = total_rows.max(1);
-        let view = viewport_rows.clamp(1, total);
-        let max_off = total.saturating_sub(view);
-
-        let thumb_len = (track * view).div_ceil(total).max(1).min(track);
-        let thumb_top = if max_off == 0 {
-            0
-        } else {
-            ((track - thumb_len) * offset + max_off / 2) / max_off
-        };
-
-        // Build lines: top arrow, track (with thumb), bottom arrow
-        let mut lines: Vec<Line> = Vec::with_capacity(scroll_area.height as usize);
-        lines.push(Line::from(Span::styled("▲", Style::default().fg(SB_ARROW))));
-        for i in 0..track {
-            if i >= thumb_top && i < thumb_top + thumb_len {
-                lines.push(Line::from(Span::styled("█", Style::default().fg(SB_THUMB))));
-            } else {
-                lines.push(Line::from(Span::styled("│", Style::default().fg(SB_TRACK))));
-            }
-        }
-        lines.push(Line::from(Span::styled("▼", Style::default().fg(SB_ARROW))));
-
-        f.render_widget(Paragraph::new(lines), scroll_area);
+    let max_off = total_rows.saturating_sub(viewport_rows);
+    if scroll_area.height >= 3 && max_off > 0 {
+        let scrollbar = Scrollbar::new(ScrollbarOrientation::VerticalRight)
+            .begin_symbol(Some("▲"))
+            .end_symbol(Some("▼"))
+            .thumb_symbol("█")
+            .track_symbol(Some("│"))
+            .thumb_style(Style::default().fg(SB_THUMB))
+            .track_style(Style::default().fg(SB_TRACK))
+            .begin_style(Style::default().fg(SB_ARROW))
+            .end_style(Style::default().fg(SB_ARROW));
+        let mut state = ScrollbarState::new(max_off).position(offset);
+        f.render_stateful_widget(scrollbar, scroll_area, &mut state);
+    }
+}
+
+#[cfg(test)]
+mod title_tests {
+    use super::*;
+
+    /// The defect this replaces: the temperature was painted over the title's tail on a
+    /// narrow pane. Whatever the width, the two must fit side by side on the border.
+    #[test]
+    fn title_and_temperature_never_overlap() {
+        for width in 0..=200u16 {
+            let (title, temp) = cpu_title_for_width(Some(3.4), 12.7, Some(43.0), width);
+            let budget = width.saturating_sub(4);
+            if temp.is_empty() {
+                continue;
+            }
+            assert!(
+                cols(&title) + cols(&temp) + TITLE_GAP <= budget,
+                "width {width}: {title:?} + {temp:?} do not fit in {budget} columns"
+            );
+        }
+    }
+
+    /// The current CPU reading is the one thing the pane must always show.
+    #[test]
+    fn the_current_reading_always_survives() {
+        for width in 20..=200u16 {
+            let (title, _) = cpu_title_for_width(Some(3.4), 12.7, Some(43.0), width);
+            assert!(
+                title.contains("3.4"),
+                "width {width}: lost the reading ({title:?})"
+            );
+        }
+    }
+
+    /// The ladder from the design: temp label, then now/avg labels, then the average,
+    /// then the temperature's decimal, then the temperature.
+    #[test]
+    fn detail_is_dropped_in_priority_order() {
+        let at = |w| cpu_title_for_width(Some(0.7), 1.3, Some(43.0), w);
+
+        let (title, temp) = at(80);
+        assert_eq!(title, "CPU (now:   0.7% | avg:   1.3%)");
+        assert_eq!(temp, "CPU Temp: 43.0°C 😎");
+
+        // The "CPU Temp:" label goes first; the readings keep their labels.
+        let (title, temp) = at(50);
+        assert_eq!(title, "CPU (now:   0.7% | avg:   1.3%)");
+        assert_eq!(temp, "43.0°C 😎");
+
+        // Then the now:/avg: labels.
+        let (title, temp) = at(40);
+        assert_eq!(title, "CPU (0.7% | 1.3%)");
+        assert_eq!(temp, "43.0°C 😎");
+
+        // Then the temperature's decimal.
+        let (title, temp) = at(31);
+        assert_eq!(title, "CPU (0.7% | 1.3%)");
+        assert_eq!(temp, "43°C 😎");
+
+        // Then the average reading.
+        let (title, temp) = at(26);
+        assert_eq!(title, "CPU (0.7%)");
+        assert_eq!(temp, "43°C 😎");
+
+        // Last of all, the temperature itself.
+        let (title, temp) = at(15);
+        assert_eq!(title, "CPU (0.7%)");
+        assert_eq!(temp, "");
+    }
+
+    /// A hot CPU has to stay visible as a warning, so the glyph rides along with the
+    /// reading at every tier that shows a temperature at all.
+    #[test]
+    fn the_thermal_glyph_tracks_the_temperature() {
+        for (t, icon) in [(43.0, "😎"), (70.0, "⚠️"), (92.0, "🔥")] {
+            for width in 26..=80u16 {
+                let (_, temp) = cpu_title_for_width(Some(0.7), 1.3, Some(t), width);
+                assert!(
+                    temp.contains(icon),
+                    "width {width} at {t}°C: expected {icon} in {temp:?}"
+                );
+            }
+        }
+    }
+
+    /// An agent that reports no temperature must not leave a stray label behind.
+    #[test]
+    fn a_missing_temperature_degrades_to_nothing() {
+        let (_, temp) = cpu_title_for_width(Some(0.7), 1.3, None, 80);
+        assert_eq!(temp, "CPU Temp: N/A");
+        let (_, temp) = cpu_title_for_width(Some(0.7), 1.3, None, 14);
+        assert_eq!(temp, "");
+    }
+
+    /// Before the first payload arrives there are no readings to show.
+    #[test]
+    fn no_metrics_yet_shows_the_placeholder() {
+        let (title, temp) = cpu_title_for_width(None, 0.0, None, 80);
+        assert_eq!(title, "CPU avg");
+        assert!(temp.is_empty());
+    }
+}
+
+#[cfg(test)]
+mod render_tests {
+    use super::*;
+    use ratatui::Terminal;
+    use ratatui::backend::TestBackend;
+    use socktop_connector::Metrics;
+
+    fn fake_metrics(cores: Vec<f32>) -> Metrics {
+        Metrics {
+            sampled_at_ms: None,
+            cpu_total: 0.0,
+            cpu_per_core: cores,
+            mem_total: 1024,
+            mem_used: 0,
+            swap_total: 0,
+            swap_used: 0,
+            hostname: "t".into(),
+            cpu_temp_c: None,
+            disks: vec![],
+            networks: vec![],
+            top_processes: vec![],
+            gpus: None,
+            process_count: Some(0),
+        }
+    }
+
+    fn dump(terminal: &Terminal<TestBackend>) -> String {
+        let buf = terminal.backend().buffer();
+        let mut out = String::new();
+        for y in 0..buf.area().height {
+            for x in 0..buf.area().width {
+                out.push_str(buf[(x, y)].symbol());
+            }
+            out.push('\n');
+        }
+        out
+    }
+
+    /// Regression: the "flat" trend glyph used to be `╌` (U+254C), then `·`
+    /// (U+00B7) — both substituted as a hyphen on terminals with narrow font
+    /// coverage. When a core sat at exactly 100% the label rendered as
+    /// `cpu3 -100.0%` (no space between trend and digits). Now we use a
+    /// literal space for the flat case AND insert a hard space between every
+    /// trend mark and the number, so no glyph substitution can produce a
+    /// "-100" substring. We assert that across flat AND transitioning cores.
+    #[test]
+    fn percore_label_never_renders_as_negative() {
+        let m = fake_metrics(vec![100.0, 100.0, 100.0, 100.0]);
+        let mut hist = PerCoreHistory::new(60);
+        hist.ensure_cores(4);
+        // First sample: history is empty, no trend on first frame.
+        hist.push_samples(&m.cpu_per_core);
+        // Second sample: identical values → flat trend (the user's complaint).
+        hist.push_samples(&m.cpu_per_core);
+
+        let backend = TestBackend::new(120, 8);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal
+            .draw(|f| {
+                draw_per_core_bars(f, Rect::new(0, 0, 120, 8), Some(&m), &mut hist, 0);
+            })
+            .unwrap();
+
+        let out = dump(&terminal);
+        eprintln!("---flat 100% render---\n{out}");
+        assert!(!out.contains("-100"), "found '-100' in flat-trend render");
+
+        // Decreasing trend at saturation: hist was high, current drops a bit.
+        let mut hist2 = PerCoreHistory::new(60);
+        hist2.ensure_cores(4);
+        for _ in 0..25 {
+            hist2.push_samples(&[100.0, 100.0, 100.0, 100.0]);
+        }
+        let m2 = fake_metrics(vec![100.0, 100.0, 100.0, 80.0]);
+        hist2.push_samples(&m2.cpu_per_core);
+
+        let backend = TestBackend::new(120, 8);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal
+            .draw(|f| {
+                draw_per_core_bars(f, Rect::new(0, 0, 120, 8), Some(&m2), &mut hist2, 0);
+            })
+            .unwrap();
+
+        let out = dump(&terminal);
+        eprintln!("---decreasing render---\n{out}");
+        assert!(
+            !out.contains("-100"),
+            "found '-100' in decreasing-trend render"
+        );
+        assert!(
+            !out.contains("-80"),
+            "found '-80' in decreasing-trend render"
+        );
     }
 }

socktop/src/ui/disks.rs

@@ -1,7 +1,8 @@
 //! Disk cards with per-device gauge and title line.
 
 use crate::types::Metrics;
-use crate::ui::util::{disk_icon, human, truncate_middle};
+use crate::ui::fit::truncate_middle_cols;
+use crate::ui::util::{disk_icon, human};
 use ratatui::{
     layout::{Constraint, Direction, Layout, Rect},
     style::Style,
@@ -24,16 +25,11 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         return;
     }
 
-    // Filter duplicates by keeping first occurrence of each unique name
-    let mut seen_names = std::collections::HashSet::new();
-    let unique_disks: Vec<_> = mm
-        .disks
-        .iter()
-        .filter(|d| seen_names.insert(d.name.clone()))
-        .collect();
-
+    // Deduplication is performed once on the App side when fresh disk data
+    // arrives (disks poll cadence is 5s, draw cadence is ~500ms, so doing it
+    // here would rebuild a HashSet ~10x per refresh for no reason).
     let per_disk_h = 3u16;
-    let max_cards = (inner.height / per_disk_h).min(unique_disks.len() as u16) as usize;
+    let max_cards = (inner.height / per_disk_h).min(mm.disks.len() as u16) as usize;
 
     let constraints: Vec<Constraint> = (0..max_cards)
         .map(|_| Constraint::Length(per_disk_h))
@@ -44,7 +40,7 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         .split(inner);
 
     for (i, slot) in rows.iter().enumerate() {
-        let d = unique_disks[i];
+        let d = &mm.disks[i];
         let used = d.total.saturating_sub(d.available);
         let ratio = if d.total > 0 {
             used as f64 / d.total as f64
@@ -74,7 +70,7 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
             "{}{}{}{}  {} / {}  ({}%)",
             indent,
             disk_icon(&d.name),
-            truncate_middle(&d.name, (slot.width.saturating_sub(6)) as usize / 2),
+            truncate_middle_cols(&d.name, slot.width.saturating_sub(6) / 2),
             temp_str,
             human(used),
             human(d.total),

socktop/src/ui/fit.rs

@@ -0,0 +1,190 @@
+//! Fitting text to the columns actually available.
+//!
+//! Several panes paint two independent pieces of text onto one row — a left title and a
+//! right-aligned readout. Nothing reserves space for the right piece, so on a narrow
+//! terminal the right one is simply painted over the tail of the left one and the title
+//! is clobbered mid-word. The helpers here let a caller measure in real terminal columns
+//! and pick the richest wording that still fits, so the two never overlap.
+//!
+//! Note that `str::len()` is a byte count and must not be used for this: `⏱` is three
+//! bytes wide but one column, and `🔒` is four bytes but two columns.
+
+use unicode_width::UnicodeWidthStr;
+
+/// Terminal columns `s` occupies, saturating at `u16::MAX`.
+pub fn cols(s: &str) -> u16 {
+    UnicodeWidthStr::width(s).min(u16::MAX as usize) as u16
+}
+
+/// Shortens `s` to at most `max` columns, marking the cut with `…`.
+///
+/// Cuts on character boundaries and accounts for wide characters, so the result never
+/// exceeds `max` columns and never splits a multi-byte character.
+pub fn truncate_cols(s: &str, max: u16) -> String {
+    if cols(s) <= max {
+        return s.to_string();
+    }
+    if max == 0 {
+        return String::new();
+    }
+    // Reserve one column for the ellipsis.
+    let budget = max.saturating_sub(1);
+    let mut used = 0u16;
+    let mut out = String::new();
+    for ch in s.chars() {
+        let w = cols(ch.encode_utf8(&mut [0u8; 4]));
+        if used + w > budget {
+            break;
+        }
+        used += w;
+        out.push(ch);
+    }
+    out.push('…');
+    out
+}
+
+/// Shortens `s` to at most `max` columns by cutting the MIDDLE, marking the
+/// cut with `…` — device names like `/dev/nvme0n1p1` keep their distinctive
+/// prefix and suffix. Column- and char-boundary-safe; the byte-slicing
+/// predecessor in `util.rs` panicked on non-ASCII names.
+pub fn truncate_middle_cols(s: &str, max: u16) -> String {
+    if cols(s) <= max {
+        return s.to_string();
+    }
+    if max <= 1 {
+        return truncate_cols(s, max);
+    }
+    // Reserve one column for the ellipsis; split the rest left/right.
+    let left_budget = (max - 1) / 2;
+    let right_budget = max - 1 - left_budget;
+
+    let mut left_end = 0; // byte index
+    let mut used = 0u16;
+    for (i, ch) in s.char_indices() {
+        let w = cols(ch.encode_utf8(&mut [0u8; 4]));
+        if used + w > left_budget {
+            break;
+        }
+        used += w;
+        left_end = i + ch.len_utf8();
+    }
+
+    let mut right_start = s.len();
+    let mut used = 0u16;
+    for (i, ch) in s.char_indices().rev() {
+        let w = cols(ch.encode_utf8(&mut [0u8; 4]));
+        if used + w > right_budget || i < left_end {
+            break;
+        }
+        used += w;
+        right_start = i;
+    }
+
+    format!("{}…{}", &s[..left_end], &s[right_start..])
+}
+
+/// Picks the first (richest) candidate pair that fits side by side in `width` columns
+/// with at least `gap` columns between them.
+///
+/// Candidates are ordered most- to least-detailed; the last one is the floor and is
+/// returned even if it does not fit, so callers always get something to render.
+pub fn pick_pair<'a>(
+    width: u16,
+    gap: u16,
+    candidates: &[(&'a str, &'a str)],
+) -> (&'a str, &'a str) {
+    let fits = |left: &str, right: &str| {
+        let needed = cols(left)
+            .saturating_add(cols(right))
+            .saturating_add(if right.is_empty() { 0 } else { gap });
+        needed <= width
+    };
+    for &(left, right) in candidates {
+        if fits(left, right) {
+            return (left, right);
+        }
+    }
+    candidates.last().copied().unwrap_or(("", ""))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// The bug these helpers exist to prevent: byte length overstates the width of the
+    /// glyphs socktop puts in its header, which is what pushed the right-hand text into
+    /// the title in the first place.
+    #[test]
+    fn cols_counts_columns_not_bytes() {
+        assert_eq!(cols("abc"), 3);
+        // Stopwatch: 3 bytes, 1 column.
+        assert_eq!("⏱".len(), 3);
+        assert_eq!(cols("⏱"), 1);
+        // Lock: 4 bytes, 2 columns.
+        assert_eq!("🔒".len(), 4);
+        assert_eq!(cols("🔒"), 2);
+        assert_eq!(cols("⏱ 500ms metrics | 2000ms procs"), 30);
+    }
+
+    #[test]
+    fn truncate_respects_the_column_budget() {
+        assert_eq!(truncate_cols("cachyos-gaming", 20), "cachyos-gaming");
+        assert_eq!(truncate_cols("cachyos-gaming", 14), "cachyos-gaming");
+        assert_eq!(truncate_cols("cachyos-gaming", 10), "cachyos-g…");
+        assert_eq!(cols(&truncate_cols("cachyos-gaming", 10)), 10);
+        assert_eq!(truncate_cols("cachyos-gaming", 1), "…");
+        assert_eq!(truncate_cols("cachyos-gaming", 0), "");
+    }
+
+    /// Truncation must never land mid-character or overrun the budget on wide glyphs.
+    #[test]
+    fn truncate_handles_wide_and_multibyte_characters() {
+        for max in 0..12u16 {
+            let out = truncate_cols("🔒🔒🔒 TLS", max);
+            assert!(cols(&out) <= max, "{out:?} exceeds {max} columns");
+            assert!(out.chars().all(|c| c != '\u{fffd}'), "{out:?} split a char");
+        }
+        // A wide glyph that cannot fit beside the ellipsis is dropped whole.
+        assert_eq!(truncate_cols("🔒ab", 2), "…");
+    }
+
+    /// Middle truncation keeps both ends — the parts that identify a device —
+    /// and must never exceed the budget or split a character.
+    #[test]
+    fn truncate_middle_keeps_both_ends_within_budget() {
+        assert_eq!(truncate_middle_cols("/dev/nvme0n1p1", 20), "/dev/nvme0n1p1");
+        let out = truncate_middle_cols("/dev/nvme0n1p1", 9);
+        assert_eq!(cols(&out), 9);
+        assert!(out.starts_with("/dev"), "{out}");
+        assert!(out.ends_with("1p1"), "{out}");
+        assert!(out.contains('…'), "{out}");
+        // Non-ASCII names must not panic (the old byte-slicing version did).
+        for max in 0..12u16 {
+            let out = truncate_middle_cols("диск-🗄️-данные", max);
+            assert!(cols(&out) <= max.max(1), "{out:?} exceeds {max}");
+        }
+    }
+
+    #[test]
+    fn pick_pair_takes_the_richest_that_fits() {
+        let candidates = [
+            ("full left text", "full right text"),
+            ("left text", "right text"),
+            ("left", "right"),
+        ];
+        assert_eq!(pick_pair(80, 2, &candidates), candidates[0]);
+        assert_eq!(pick_pair(24, 2, &candidates), candidates[1]);
+        assert_eq!(pick_pair(12, 2, &candidates), candidates[2]);
+        // Below the floor the last candidate is still returned.
+        assert_eq!(pick_pair(1, 2, &candidates), candidates[2]);
+    }
+
+    /// The gap is what keeps the two pieces from touching; it must not be charged when
+    /// there is no right-hand piece to separate.
+    #[test]
+    fn pick_pair_only_charges_the_gap_when_both_sides_are_present() {
+        let candidates = [("0123456789", "x"), ("0123456789", "")];
+        assert_eq!(pick_pair(11, 2, &candidates), candidates[1]);
+        assert_eq!(pick_pair(13, 2, &candidates), candidates[0]);
+    }
+}

socktop/src/ui/gpu.rs

@@ -121,3 +121,210 @@ pub fn draw_gpu(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         );
     }
 }
+
+/// One-line GPU strip for compact mode: no device name (it is the first thing to lose
+/// value when rows are scarce), just utilisation and VRAM on the single content row
+/// between the block borders. Only the first GPU fits; the title says so when there are
+/// more.
+pub fn draw_gpu_compact(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
+    let gpus = m.and_then(|mm| mm.gpus.as_ref());
+    let count = gpus.map(|g| g.len()).unwrap_or(0);
+    let title = if count > 1 {
+        format!("GPU (1/{count})")
+    } else {
+        "GPU".to_string()
+    };
+    f.render_widget(Block::default().borders(Borders::ALL).title(title), area);
+
+    if area.height < 3 || area.width <= 2 {
+        return;
+    }
+    let inner = Rect {
+        x: area.x + 1,
+        y: area.y + 1,
+        width: area.width - 2,
+        height: 1,
+    };
+
+    let Some(g) = gpus.and_then(|v| v.first()) else {
+        f.render_widget(Paragraph::new("No GPUs"), inner);
+        return;
+    };
+
+    let util = g.utilization.unwrap_or(0.0).clamp(0.0, 100.0) as u16;
+    let used = g.mem_used.unwrap_or(0);
+    let total = g.mem_total.unwrap_or(1);
+    let mem_ratio = if total > 0 {
+        (used as f64 / total as f64).clamp(0.0, 1.0)
+    } else {
+        0.0
+    };
+    let util_label = format!("util: {util}%");
+    let mem_label = format!(
+        "vram: {}/{} ({}%)",
+        fmt_bytes(used),
+        fmt_bytes(total),
+        (mem_ratio * 100.0).round() as u16
+    );
+
+    // Bars are sized explicitly rather than left to stretch: an idle bar renders as
+    // empty cells, so a full-width one turns into a long blank run between two labels.
+    const MIN_GAUGE_W: u16 = 6;
+    const MAX_GAUGE_W: u16 = 24;
+    let labels_w = util_label.len() as u16 + mem_label.len() as u16 + 4; // one space each side
+    let gauge_w = inner
+        .width
+        .saturating_sub(labels_w)
+        .min(2 * MAX_GAUGE_W)
+        .div_euclid(2);
+
+    // Too narrow for bars worth drawing: keep the numbers, drop the bars.
+    if gauge_w < MIN_GAUGE_W {
+        f.render_widget(
+            Paragraph::new(Span::raw(format!("{util_label}  {mem_label}")))
+                .style(Style::default().fg(Color::Gray)),
+            inner,
+        );
+        return;
+    }
+
+    // Each label leads its own bar. Bar-then-label (as the tall panel does) is ambiguous
+    // on a single line: with an idle bar rendering empty, the next pair's fill ends up
+    // flush against the previous pair's text and reads as belonging to it.
+    let mut x = inner.x;
+    let mut place = |w: u16| {
+        let r = Rect {
+            x,
+            y: inner.y,
+            width: w,
+            height: 1,
+        };
+        x += w;
+        r
+    };
+    let util_rect = place(util_label.len() as u16 + 2);
+    let util_bar = place(gauge_w);
+    let mem_rect = place(mem_label.len() as u16 + 2);
+    let mem_bar = place(gauge_w);
+
+    let label = |text: &str| {
+        Paragraph::new(Span::raw(format!(" {text} "))).style(Style::default().fg(Color::Gray))
+    };
+
+    f.render_widget(label(&util_label), util_rect);
+    f.render_widget(
+        Gauge::default()
+            .gauge_style(Style::default().fg(Color::Green))
+            .label(Span::raw(""))
+            .ratio(util as f64 / 100.0),
+        util_bar,
+    );
+    f.render_widget(label(&mem_label), mem_rect);
+    f.render_widget(
+        Gauge::default()
+            .gauge_style(Style::default().fg(Color::LightMagenta))
+            .label(Span::raw(""))
+            .ratio(mem_ratio),
+        mem_bar,
+    );
+}
+
+#[cfg(test)]
+mod render_tests {
+    use super::*;
+    use ratatui::Terminal;
+    use ratatui::backend::TestBackend;
+    use socktop_connector::{GpuInfo, Metrics};
+
+    fn gpu(name: &str) -> GpuInfo {
+        GpuInfo {
+            name: Some(name.into()),
+            vendor: None,
+            utilization: Some(42.0),
+            mem_used: Some(4_724_464_025),
+            mem_total: Some(17_070_817_280),
+            temp: None,
+        }
+    }
+
+    fn metrics(gpus: Option<Vec<GpuInfo>>) -> Metrics {
+        Metrics {
+            sampled_at_ms: None,
+            cpu_total: 0.0,
+            cpu_per_core: vec![],
+            mem_total: 1024,
+            mem_used: 0,
+            swap_total: 0,
+            swap_used: 0,
+            hostname: "t".into(),
+            cpu_temp_c: None,
+            disks: vec![],
+            networks: vec![],
+            top_processes: vec![],
+            gpus,
+            process_count: Some(0),
+        }
+    }
+
+    fn render(width: u16, m: &Metrics) -> String {
+        let mut terminal = Terminal::new(TestBackend::new(width, 3)).unwrap();
+        terminal
+            .draw(|f| draw_gpu_compact(f, Rect::new(0, 0, width, 3), Some(m)))
+            .unwrap();
+        let buf = terminal.backend().buffer();
+        let mut out = String::new();
+        for y in 0..buf.area().height {
+            for x in 0..buf.area().width {
+                out.push_str(buf[(x, y)].symbol());
+            }
+            out.push('\n');
+        }
+        out
+    }
+
+    /// Compact mode drops the device name — the row is one line and the numbers are
+    /// what the space is for.
+    #[test]
+    fn compact_strip_omits_the_device_name() {
+        let m = metrics(Some(vec![gpu("NVIDIA GeForce RTX 5080")]));
+        let out = render(80, &m);
+        assert!(
+            !out.contains("NVIDIA"),
+            "name leaked into compact strip:\n{out}"
+        );
+        assert!(out.contains("util: 42%"), "{out}");
+        assert!(out.contains("vram: 4.4G/15.9G (28%)"), "{out}");
+    }
+
+    /// A second GPU cannot fit on one line, so the title has to say the strip is partial
+    /// rather than silently showing only the first card.
+    #[test]
+    fn multiple_gpus_are_flagged_in_the_title() {
+        let one = render(80, &metrics(Some(vec![gpu("a")])));
+        assert!(one.contains("GPU") && !one.contains("1/"), "{one}");
+
+        let two = render(80, &metrics(Some(vec![gpu("a"), gpu("b")])));
+        assert!(two.contains("GPU (1/2)"), "{two}");
+    }
+
+    /// Narrow terminals drop the gauges rather than rendering two-cell stubs, but must
+    /// never drop the numbers.
+    #[test]
+    fn narrow_strip_keeps_the_numbers() {
+        let m = metrics(Some(vec![gpu("a")]));
+        for width in [20u16, 30, 40, 47, 48, 80, 200] {
+            let out = render(width, &m);
+            if width >= 40 {
+                assert!(out.contains("util: 42%"), "width {width}:\n{out}");
+            }
+            // No panic, and the block always closes on the last row.
+            assert_eq!(out.lines().count(), 3, "width {width}");
+        }
+    }
+
+    #[test]
+    fn missing_gpu_payload_does_not_panic() {
+        assert!(render(80, &metrics(None)).contains("No GPUs"));
+        assert!(render(80, &metrics(Some(vec![]))).contains("No GPUs"));
+    }
+}

socktop/src/ui/header.rs

@@ -1,55 +1,232 @@
-//! Top header with hostname and CPU temperature indicator.
+//! Top header with hostname, connection status and polling intervals.
+//!
+//! The row carries two pieces of text — session identity on the left, polling intervals
+//! on the right — and both matter. Rather than let the right one overwrite the left when
+//! they no longer both fit, the header drops detail in priority order: the hostname and
+//! the intervals are what survive longest, because they are what tells you *which* host
+//! you are looking at and how fresh the numbers are.
 
-use crate::types::Metrics;
+use crate::ui::fit::{cols, pick_pair, truncate_cols};
 use ratatui::{
     layout::Rect,
     text::{Line, Span},
     widgets::{Block, Borders, Paragraph},
 };
-use std::time::Duration;
 
-pub fn draw_header(
-    f: &mut ratatui::Frame<'_>,
-    area: Rect,
-    m: Option<&Metrics>,
-    is_tls: bool,
-    has_token: bool,
-    metrics_interval: Duration,
-    procs_interval: Duration,
-) {
-    let base = if let Some(mm) = m {
-        format!("socktop — host: {}", mm.hostname)
+/// Columns kept clear between the left and right halves.
+const GAP: u16 = 2;
+/// Never shorten the hostname below this before dropping the intervals instead.
+const HOSTNAME_FLOOR: u16 = 8;
+
+/// Session state the header renders.
+#[derive(Clone, Copy)]
+pub struct HeaderState<'a> {
+    pub hostname: Option<&'a str>,
+    pub is_tls: bool,
+    pub has_token: bool,
+    pub metrics_ms: u128,
+    pub procs_ms: u128,
+}
+
+/// Builds the left and right halves of the header for a row `width` columns wide.
+///
+/// Detail is dropped in this order as the row narrows: the key hints, then the TLS/token
+/// badges, then the `socktop — host:` prefix (leaving the bare hostname), then the
+/// `metrics`/`procs` words, and only then is the hostname itself shortened. The two
+/// halves are always sized to sit side by side, so neither can paint over the other.
+///
+/// Callers cache the result and rebuild it only when the state or the width changes.
+pub fn build_header(state: HeaderState<'_>, width: u16) -> (String, String) {
+    let host = state.hostname.unwrap_or("connecting...");
+    let tls = if state.is_tls {
+        "🔒 TLS"
     } else {
-        "socktop — connecting...".into()
+        "🔒✗ TLS"
+    };
+    let badges = if state.has_token {
+        format!("{tls} | 🔑 token")
+    } else {
+        tls.to_string()
     };
-    // TLS indicator: lock vs lock with cross (using ✗). Keep explicit label for clarity.
-    let tls_txt = if is_tls { "🔒 TLS" } else { "🔒✗ TLS" };
-    // Token indicator
-    let tok_txt = if has_token { "🔑 token" } else { "" };
-    let mut parts = vec![base, tls_txt.into()];
-    if !tok_txt.is_empty() {
-        parts.push(tok_txt.into());
-    }
-    parts.push("(a: about, h: help, q: quit)".into());
-    let title = parts.join(" | ");
 
-    // Render the block with left-aligned title
+    let named = format!("socktop — host: {host}");
+    let with_badges = format!("{named} | {badges}");
+    let with_keys = format!("{with_badges} | (a: about, h: help, q: quit)");
+
+    let intervals = format!(
+        "⏱ {}ms metrics | {}ms procs",
+        state.metrics_ms, state.procs_ms
+    );
+    let intervals_short = format!("⏱ {}ms | {}ms", state.metrics_ms, state.procs_ms);
+
+    // Richest first. The bare hostname is reached before the intervals lose their
+    // labels, and the hostname is only shortened once nothing else is left to give.
+    let ladder = [
+        (with_keys.as_str(), intervals.as_str()),
+        (with_badges.as_str(), intervals.as_str()),
+        (named.as_str(), intervals.as_str()),
+        (host, intervals.as_str()),
+        (host, intervals_short.as_str()),
+    ];
+    let (left, right) = pick_pair(width, GAP, &ladder);
+    if cols(left) + cols(right) + GAP <= width {
+        return (left.to_string(), right.to_string());
+    }
+
+    // Past the floor of the ladder: shorten the hostname, and give up the intervals only
+    // if even a stub of a hostname will not fit beside them.
+    let room = width
+        .saturating_sub(cols(&intervals_short))
+        .saturating_sub(GAP);
+    if room >= HOSTNAME_FLOOR {
+        return (truncate_cols(host, room), intervals_short);
+    }
+    (truncate_cols(host, width), String::new())
+}
+
+pub fn draw_header(f: &mut ratatui::Frame<'_>, area: Rect, title: &str, intervals: &str) {
     f.render_widget(Block::default().title(title).borders(Borders::BOTTOM), area);
 
-    // Render polling intervals on the right side
-    let mi = metrics_interval.as_millis();
-    let pi = procs_interval.as_millis();
-    let intervals = format!("⏱ {mi}ms metrics | {pi}ms procs");
-    let intervals_width = intervals.len() as u16;
-
-    if area.width > intervals_width + 2 {
+    if intervals.is_empty() {
+        return;
+    }
+    let intervals_width = cols(intervals);
+    if area.width >= intervals_width {
         let right_area = Rect {
-            x: area.x + area.width.saturating_sub(intervals_width + 1),
+            x: area.x + area.width - intervals_width,
             y: area.y,
             width: intervals_width,
             height: 1,
         };
-        let intervals_line = Line::from(Span::raw(intervals));
-        f.render_widget(Paragraph::new(intervals_line), right_area);
+        f.render_widget(Paragraph::new(Line::from(Span::raw(intervals))), right_area);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn state(hostname: Option<&str>) -> HeaderState<'_> {
+        HeaderState {
+            hostname,
+            is_tls: false,
+            has_token: false,
+            metrics_ms: 500,
+            procs_ms: 2000,
+        }
+    }
+
+    /// The defect this replaces: the two halves were painted independently, so below
+    /// ~105 columns the right half landed on top of the title. Whatever the width, they
+    /// must now fit side by side.
+    #[test]
+    fn halves_never_overlap_at_any_width() {
+        for width in 0..=200u16 {
+            let (left, right) = build_header(state(Some("cachyos-gaming")), width);
+            let used = cols(&left) + cols(&right);
+            if right.is_empty() {
+                assert!(cols(&left) <= width, "width {width}: {left:?} overflows");
+            } else {
+                assert!(
+                    used + GAP <= width,
+                    "width {width}: {left:?} + {right:?} = {used} cols, no room for both"
+                );
+            }
+        }
+    }
+
+    /// Hostname and intervals are the two things worth keeping; everything else is
+    /// context that can go.
+    #[test]
+    fn hostname_and_intervals_survive_longest() {
+        for width in 34..=200u16 {
+            let (left, right) = build_header(state(Some("cachyos-gaming")), width);
+            assert!(
+                left.contains("cachyos-gaming"),
+                "width {width}: lost the hostname ({left:?})"
+            );
+            assert!(
+                right.contains("500ms") && right.contains("2000ms"),
+                "width {width}: lost the intervals ({right:?})"
+            );
+        }
+    }
+
+    /// The ladder from the design: key hints, then badges, then the prefix, then the
+    /// interval labels, then the hostname itself.
+    #[test]
+    fn detail_is_dropped_in_priority_order() {
+        let s = state(Some("cachyos-gaming"));
+
+        let (left, right) = build_header(s, 120);
+        assert_eq!(
+            left,
+            "socktop — host: cachyos-gaming | 🔒✗ TLS | (a: about, h: help, q: quit)"
+        );
+        assert_eq!(right, "⏱ 500ms metrics | 2000ms procs");
+
+        // Key hints go first.
+        let (left, _) = build_header(s, 80);
+        assert_eq!(left, "socktop — host: cachyos-gaming | 🔒✗ TLS");
+
+        // Then the badges.
+        let (left, _) = build_header(s, 70);
+        assert_eq!(left, "socktop — host: cachyos-gaming");
+
+        // Then the prefix, leaving the bare hostname.
+        let (left, right) = build_header(s, 50);
+        assert_eq!(left, "cachyos-gaming");
+        assert_eq!(right, "⏱ 500ms metrics | 2000ms procs");
+
+        // Then the interval labels.
+        let (left, right) = build_header(s, 34);
+        assert_eq!(left, "cachyos-gaming");
+        assert_eq!(right, "⏱ 500ms | 2000ms");
+
+        // Only then is the hostname itself shortened.
+        // 30 columns - 16 for the short intervals - 2 gap leaves 12 for the hostname.
+        let (left, right) = build_header(s, 30);
+        assert_eq!(left, "cachyos-gam…");
+        assert_eq!(right, "⏱ 500ms | 2000ms");
+    }
+
+    /// A long hostname must not push the intervals off the row.
+    #[test]
+    fn a_long_hostname_is_shortened_rather_than_winning_the_row() {
+        let long = "a-very-long-hostname-that-will-not-fit-anywhere";
+        for width in 30..=100u16 {
+            let (left, right) = build_header(state(Some(long)), width);
+            assert!(!right.is_empty(), "width {width}: intervals were dropped");
+            assert!(cols(&left) + cols(&right) + GAP <= width, "width {width}");
+        }
+    }
+
+    /// Widths too small for both: the hostname is the last thing standing.
+    #[test]
+    fn hostname_is_the_final_survivor() {
+        let (left, right) = build_header(state(Some("cachyos-gaming")), 20);
+        assert!(right.is_empty(), "intervals should have been dropped");
+        assert!(!left.is_empty());
+        assert!(cols(&left) <= 20);
+    }
+
+    #[test]
+    fn tls_and_token_badges_appear_when_there_is_room() {
+        let s = HeaderState {
+            hostname: Some("host"),
+            is_tls: true,
+            has_token: true,
+            metrics_ms: 500,
+            procs_ms: 2000,
+        };
+        let (left, _) = build_header(s, 200);
+        assert!(left.contains("🔒 TLS"), "{left}");
+        assert!(left.contains("🔑 token"), "{left}");
+    }
+
+    #[test]
+    fn a_missing_hostname_reads_as_connecting() {
+        let (left, _) = build_header(state(None), 120);
+        assert!(left.contains("connecting"), "{left}");
     }
 }

socktop/src/ui/layout.rs

@@ -0,0 +1,352 @@
+//! Root layout computation, shared by the draw path and the input hit-testing paths.
+//!
+//! Two modes:
+//!
+//! * [`LayoutMode::Normal`] — the full layout. CPU graph and per-core bars on top,
+//!   Memory over Swap on the left with the GPU panel beside them, then Disks and the
+//!   network graphs next to the process table.
+//!
+//! * [`LayoutMode::Compact`] — entered when the window is too short for the Disks pane
+//!   to render even one complete disk card. Disks is dropped, Memory and Swap move side
+//!   by side into the space it vacated, the GPU collapses to a single full-width line
+//!   (and disappears entirely when the host has no GPU), and every row reclaimed goes to
+//!   the CPU graph and per-core bars — which in the fixed layout are squeezed to nothing
+//!   long before the rest of the panes stop being useful.
+
+use ratatui::layout::{Constraint, Direction, Layout, Rect};
+
+/// Which of the two layouts [`compute`] produced.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum LayoutMode {
+    Normal,
+    Compact,
+}
+
+impl LayoutMode {
+    pub fn is_compact(self) -> bool {
+        matches!(self, LayoutMode::Compact)
+    }
+}
+
+/// Rows the Disks pane needs before it can show one disk card: the card itself is
+/// 3 rows (`disks::draw_disks`) plus the pane's own top and bottom border.
+const DISKS_MIN_H: u16 = 5;
+
+/// Header line.
+const HEADER_H: u16 = 1;
+/// Memory and Swap gauges: 1 content row between borders.
+const GAUGE_H: u16 = 3;
+/// A network graph at its preferred height.
+const NET_H: u16 = 5;
+
+// Compact-mode budget. The top row is kept at `TOP_MIN_H` (3 content rows between
+// borders) before the network graphs are allowed to shrink, because restoring the CPU
+// panes is the entire point of the mode.
+const TOP_MIN_H: u16 = 5;
+const BOTTOM_PREF_H: u16 = GAUGE_H + 2 * NET_H;
+const BOTTOM_MIN_H: u16 = GAUGE_H + 2 * 3;
+
+/// Every pane rect for one frame. `disks` and `gpu` are `None` when the mode omits them.
+#[derive(Clone, Copy, Debug)]
+pub struct AppLayout {
+    pub mode: LayoutMode,
+    pub header: Rect,
+    pub cpu: Rect,
+    pub per_core: Rect,
+    pub gpu: Option<Rect>,
+    pub mem: Rect,
+    pub swap: Rect,
+    pub disks: Option<Rect>,
+    pub download: Rect,
+    pub upload: Rect,
+    pub procs: Rect,
+}
+
+/// Splits `area` into pane rects.
+///
+/// `force_compact` comes from `--compact` and pins the compact layout at any size.
+/// `has_gpu` decides whether compact mode reserves its one-line GPU strip; it is false
+/// until the first metrics payload arrives, so a GPU-less host never reserves the row.
+pub fn compute(area: Rect, force_compact: bool, has_gpu: bool) -> AppLayout {
+    if force_compact {
+        return compact(area, has_gpu);
+    }
+    let normal = normal(area);
+    match normal.disks {
+        Some(d) if d.height >= DISKS_MIN_H => normal,
+        _ => compact(area, has_gpu),
+    }
+}
+
+fn split(area: Rect, dir: Direction, constraints: &[Constraint]) -> std::rc::Rc<[Rect]> {
+    Layout::default()
+        .direction(dir)
+        .constraints(constraints)
+        .split(area)
+}
+
+/// 66/34 split used by every full-width row in the normal layout.
+fn left_right(area: Rect) -> std::rc::Rc<[Rect]> {
+    split(
+        area,
+        Direction::Horizontal,
+        &[Constraint::Percentage(66), Constraint::Percentage(34)],
+    )
+}
+
+fn normal(area: Rect) -> AppLayout {
+    let rows = split(
+        area,
+        Direction::Vertical,
+        &[
+            Constraint::Length(HEADER_H), // header
+            Constraint::Ratio(1, 3),      // top row
+            Constraint::Length(GAUGE_H),  // memory (left) + GPU (right, part 1)
+            Constraint::Length(GAUGE_H),  // swap (left)   + GPU (right, part 2)
+            Constraint::Min(2 * NET_H),   // bottom: disks + net (left), top procs (right)
+        ],
+    );
+
+    let top = left_right(rows[1]);
+    let mem_lr = left_right(rows[2]);
+    let swap_lr = left_right(rows[3]);
+
+    // GPU spans the same vertical space as Memory + Swap.
+    let gpu = Rect {
+        x: mem_lr[1].x,
+        y: mem_lr[1].y,
+        width: mem_lr[1].width,
+        height: mem_lr[1].height + swap_lr[1].height,
+    };
+
+    let bottom = split(
+        rows[4],
+        Direction::Horizontal,
+        &[Constraint::Percentage(60), Constraint::Percentage(40)],
+    );
+    let left_stack = split(
+        bottom[0],
+        Direction::Vertical,
+        &[
+            Constraint::Min(4),        // disks absorbs the slack
+            Constraint::Length(NET_H), // download
+            Constraint::Length(NET_H), // upload
+        ],
+    );
+
+    AppLayout {
+        mode: LayoutMode::Normal,
+        header: rows[0],
+        cpu: top[0],
+        per_core: top[1],
+        gpu: Some(gpu),
+        mem: mem_lr[0],
+        swap: swap_lr[0],
+        disks: Some(left_stack[0]),
+        download: left_stack[1],
+        upload: left_stack[2],
+        procs: bottom[1],
+    }
+}
+
+fn compact(area: Rect, has_gpu: bool) -> AppLayout {
+    let gpu_h = if has_gpu { GAUGE_H } else { 0 };
+    let avail = area.height.saturating_sub(HEADER_H + gpu_h);
+
+    // Give the top row its floor first, then share any surplus with the bottom so the
+    // process table keeps growing with the window instead of staying pinned at 13 rows.
+    let (top_h, bottom_h) = if avail >= TOP_MIN_H + BOTTOM_PREF_H {
+        let top = TOP_MIN_H + (avail - TOP_MIN_H - BOTTOM_PREF_H) / 2;
+        (top, avail - top)
+    } else if avail >= TOP_MIN_H + BOTTOM_MIN_H {
+        (TOP_MIN_H, avail - TOP_MIN_H)
+    } else {
+        // Smaller than both floors: the network graphs are already at their minimum, so
+        // the top row takes what is left (panes clip below this point).
+        let bottom = BOTTOM_MIN_H.min(avail);
+        (avail - bottom, bottom)
+    };
+
+    let rows = split(
+        area,
+        Direction::Vertical,
+        &[
+            Constraint::Length(HEADER_H),
+            Constraint::Length(top_h),
+            Constraint::Length(gpu_h),
+            Constraint::Length(bottom_h),
+        ],
+    );
+
+    let top = left_right(rows[1]);
+
+    let bottom = split(
+        rows[3],
+        Direction::Horizontal,
+        &[Constraint::Percentage(60), Constraint::Percentage(40)],
+    );
+    // Memory + Swap take the row Disks used to occupy; the graphs share what is left.
+    let left_stack = split(
+        bottom[0],
+        Direction::Vertical,
+        &[
+            Constraint::Length(GAUGE_H),
+            Constraint::Fill(1),
+            Constraint::Fill(1),
+        ],
+    );
+    let gauges = split(
+        left_stack[0],
+        Direction::Horizontal,
+        &[Constraint::Percentage(50), Constraint::Percentage(50)],
+    );
+
+    AppLayout {
+        mode: LayoutMode::Compact,
+        header: rows[0],
+        cpu: top[0],
+        per_core: top[1],
+        gpu: has_gpu.then_some(rows[2]),
+        mem: gauges[0],
+        swap: gauges[1],
+        disks: None,
+        download: left_stack[1],
+        upload: left_stack[2],
+        procs: bottom[1],
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn area(w: u16, h: u16) -> Rect {
+        Rect::new(0, 0, w, h)
+    }
+
+    /// The height where the normal layout still fits a full disk card. Below it the CPU
+    /// panes are the ones that collapse, which is what compact mode exists to prevent.
+    #[test]
+    fn tall_window_stays_normal() {
+        let l = compute(area(120, 40), false, true);
+        assert_eq!(l.mode, LayoutMode::Normal);
+        assert!(l.disks.expect("disks pane").height >= DISKS_MIN_H);
+    }
+
+    #[test]
+    fn short_window_switches_to_compact() {
+        let l = compute(area(120, 24), false, true);
+        assert_eq!(l.mode, LayoutMode::Compact);
+        assert!(l.disks.is_none());
+    }
+
+    /// The switch happens exactly when Disks can no longer show one card, and never
+    /// oscillates: every height above the crossover is normal, every height below is
+    /// compact.
+    #[test]
+    fn mode_is_monotonic_in_height() {
+        let mut first_normal = None;
+        for h in 10..=60u16 {
+            let mode = compute(area(120, h), false, true).mode;
+            match (mode, first_normal) {
+                (LayoutMode::Normal, None) => first_normal = Some(h),
+                (LayoutMode::Compact, Some(prev)) => {
+                    panic!("height {h} went back to compact after normal at {prev}")
+                }
+                _ => {}
+            }
+        }
+        assert!(first_normal.is_some(), "never reached the normal layout");
+    }
+
+    #[test]
+    fn force_compact_overrides_a_tall_window() {
+        let l = compute(area(200, 80), true, true);
+        assert_eq!(l.mode, LayoutMode::Compact);
+        assert!(l.disks.is_none());
+    }
+
+    #[test]
+    fn compact_drops_the_gpu_row_without_a_gpu() {
+        let with = compute(area(120, 24), true, true);
+        let without = compute(area(120, 24), true, false);
+        assert!(with.gpu.is_some());
+        assert_eq!(with.gpu.expect("gpu strip").height, GAUGE_H);
+        assert!(without.gpu.is_none());
+        // The rows a GPU-less host saves are shared between the CPU panes and the
+        // bottom half, and none of them are left as a gap.
+        assert!(without.cpu.height > with.cpu.height);
+        assert!(without.procs.height > with.procs.height);
+        assert_eq!(without.procs.y + without.procs.height, 24);
+    }
+
+    /// Compact exists to keep the CPU graph and per-core bars drawable: both need
+    /// content rows inside their borders.
+    #[test]
+    fn compact_keeps_the_cpu_panes_drawable() {
+        for h in 18..=32u16 {
+            let l = compute(area(120, h), false, true);
+            assert_eq!(l.mode, LayoutMode::Compact, "height {h}");
+            assert!(
+                l.cpu.height >= TOP_MIN_H,
+                "height {h}: cpu pane only {} rows",
+                l.cpu.height
+            );
+            assert_eq!(l.per_core.height, l.cpu.height);
+        }
+    }
+
+    /// Regression guard for the bug this mode fixes: at 18 rows the old fixed layout
+    /// left the top row with no drawable interior at all.
+    #[test]
+    fn compact_beats_the_fixed_layout_at_18_rows() {
+        let compact = compute(area(120, 18), false, true);
+        let fixed = normal(area(120, 18));
+        assert!(fixed.cpu.height <= 2, "fixed layout unexpectedly usable");
+        assert!(compact.cpu.height > fixed.cpu.height);
+    }
+
+    #[test]
+    fn compact_panes_tile_the_area_without_gaps() {
+        for h in 16..=32u16 {
+            for has_gpu in [true, false] {
+                let l = compute(area(120, h), true, has_gpu);
+                assert_eq!(l.header.y, 0);
+                assert_eq!(l.cpu.y, l.header.y + l.header.height);
+                assert_eq!(l.per_core.x, l.cpu.x + l.cpu.width);
+
+                let after_cpu = l.cpu.y + l.cpu.height;
+                let bottom_y = match l.gpu {
+                    Some(g) => {
+                        assert_eq!(g.y, after_cpu);
+                        assert_eq!(g.width, 120, "gpu strip spans the full width");
+                        g.y + g.height
+                    }
+                    None => after_cpu,
+                };
+                assert_eq!(l.mem.y, bottom_y);
+                // Memory and Swap sit side by side on one row.
+                assert_eq!(l.swap.y, l.mem.y);
+                assert_eq!(l.swap.x, l.mem.x + l.mem.width);
+                assert_eq!(l.mem.height, GAUGE_H);
+                assert_eq!(l.download.y, l.mem.y + l.mem.height);
+                assert_eq!(l.upload.y, l.download.y + l.download.height);
+                assert_eq!(l.procs.y, bottom_y);
+            }
+        }
+    }
+
+    /// A degenerate size must not panic or produce rects outside the frame.
+    #[test]
+    fn tiny_windows_stay_inside_the_frame() {
+        for h in 0..=16u16 {
+            for w in [0u16, 1, 20, 80] {
+                let l = compute(area(w, h), false, true);
+                for r in [l.header, l.cpu, l.per_core, l.mem, l.swap, l.procs] {
+                    assert!(r.y + r.height <= h, "{r:?} escapes height {h}");
+                    assert!(r.x + r.width <= w, "{r:?} escapes width {w}");
+                }
+            }
+        }
+    }
+}

socktop/src/ui/mod.rs

@@ -2,8 +2,10 @@
 
 pub mod cpu;
 pub mod disks;
+pub mod fit;
 pub mod gpu;
 pub mod header;
+pub mod layout;
 pub mod mem;
 pub mod modal;
 pub mod modal_connection;

socktop/src/ui/modal.rs

@@ -1,6 +1,10 @@
 //! Modal window system for socktop TUI application
 
-use super::theme::MODAL_DIM_BG;
+use super::fit;
+use super::theme::{
+    BTN_EXIT_BG_ACTIVE, BTN_RETRY_BG_ACTIVE, MODAL_BG, MODAL_BORDER_FG, MODAL_DIM_BG, MODAL_FG,
+    MODAL_TITLE_FG,
+};
 use crossterm::event::KeyCode;
 use ratatui::{
     Frame,
@@ -26,6 +30,10 @@ pub struct ModalManager {
     pub help_scroll_offset: usize,
 }
 
+/// Key hints shown under the confirmation buttons. Also sets the minimum
+/// width of that dialog — sizing from the question alone clipped this line.
+const CONFIRM_HINT: &str = "Tab ← → choose  ·  Enter run  ·  Esc cancel";
+
 impl ModalManager {
     pub fn new() -> Self {
         Self {
@@ -83,6 +91,52 @@ impl ModalManager {
         }
         m
     }
+    /// Close the details view for `pid` WHEREVER it sits in the stack.
+    /// Returns whether anything was closed.
+    ///
+    /// Not just the top: killing from inside the details view stacks the
+    /// "Signal sent" Info modal on top of it, and a SIGKILL victim is usually
+    /// confirmed dead on the very next tick — while that Info is still up. A
+    /// top-only check missed the close, and since a gone PID is processed
+    /// once, the details view stayed open (frozen on the dead process's last
+    /// sample) with nothing left to ever close it.
+    ///
+    /// Per-PID matching keeps the parent-navigation property: only the dead
+    /// process's view goes; parent views underneath are other processes that
+    /// may still be alive and close themselves the same way.
+    pub fn close_process_details(&mut self, pid: u32) -> bool {
+        let was_top =
+            matches!(self.stack.last(), Some(ModalType::ProcessDetails { pid: p }) if *p == pid);
+        let before = self.stack.len();
+        self.stack
+            .retain(|m| !matches!(m, ModalType::ProcessDetails { pid: p } if *p == pid));
+        if self.stack.len() == before {
+            return false;
+        }
+        // Mirror pop_modal's focus bookkeeping when the top changed.
+        if was_top && let Some(next) = self.stack.last() {
+            self.active_button = match next {
+                ModalType::ConnectionError { .. } => ModalButton::Retry,
+                ModalType::ProcessDetails { .. } => ModalButton::Ok,
+                ModalType::About => ModalButton::Ok,
+                ModalType::Help => ModalButton::Ok,
+                ModalType::Confirmation { .. } => ModalButton::Confirm,
+                ModalType::Info { .. } => ModalButton::Ok,
+            };
+        }
+        true
+    }
+
+    /// PID of the uppermost ProcessDetails view, looking through any
+    /// Info/Confirmation stacked above it. What the user will land on when
+    /// transient modals are dismissed.
+    pub fn topmost_process_details(&self) -> Option<u32> {
+        self.stack.iter().rev().find_map(|m| match m {
+            ModalType::ProcessDetails { pid } => Some(*pid),
+            _ => None,
+        })
+    }
+
     pub fn update_connection_error_countdown(&mut self, new_countdown: Option<u64>) {
         if let Some(ModalType::ConnectionError {
             auto_retry_countdown,
@@ -110,6 +164,16 @@ impl ModalManager {
                 self.prev_button();
                 ModalAction::None
             }
+            // Kill the process being viewed. `t` rather than `k` because `k`
+            // scrolls the thread table in this modal — and using the same key
+            // here as on the processes pane means one thing to remember.
+            KeyCode::Char('t') | KeyCode::Char('T') => {
+                if let Some(ModalType::ProcessDetails { pid }) = self.stack.last() {
+                    ModalAction::KillSelected(*pid)
+                } else {
+                    ModalAction::None
+                }
+            }
             KeyCode::Char('r') | KeyCode::Char('R') => {
                 if matches!(self.stack.last(), Some(ModalType::ConnectionError { .. })) {
                     ModalAction::RetryConnection
@@ -241,7 +305,16 @@ impl ModalManager {
                 ModalAction::Dismiss
             }
             (Some(ModalType::Confirmation { .. }), ModalButton::Confirm) => ModalAction::Confirm,
-            (Some(ModalType::Confirmation { .. }), ModalButton::Cancel) => ModalAction::Cancel,
+            (Some(ModalType::Confirmation { .. }), ModalButton::ConfirmForce) => {
+                ModalAction::ConfirmForce
+            }
+            (Some(ModalType::Confirmation { .. }), ModalButton::Cancel) => {
+                // Pop here so Enter-on-Cancel behaves like Esc (which pops in
+                // handle_key); the app's Cancel handler can then assume the
+                // modal is already gone.
+                self.pop_modal();
+                ModalAction::Cancel
+            }
             (Some(ModalType::Info { .. }), ModalButton::Ok) => {
                 self.pop_modal();
                 ModalAction::Dismiss
@@ -253,12 +326,29 @@ impl ModalManager {
         self.active_button = match (&self.stack.last(), &self.active_button) {
             (Some(ModalType::ConnectionError { .. }), ModalButton::Retry) => ModalButton::Exit,
             (Some(ModalType::ConnectionError { .. }), ModalButton::Exit) => ModalButton::Retry,
-            (Some(ModalType::Confirmation { .. }), ModalButton::Confirm) => ModalButton::Cancel,
+            // Confirmation cycles through three: the safe affirmative, the
+            // escalated one, then cancel.
+            (Some(ModalType::Confirmation { .. }), ModalButton::Confirm) => {
+                ModalButton::ConfirmForce
+            }
+            (Some(ModalType::Confirmation { .. }), ModalButton::ConfirmForce) => {
+                ModalButton::Cancel
+            }
             (Some(ModalType::Confirmation { .. }), ModalButton::Cancel) => ModalButton::Confirm,
             _ => self.active_button.clone(),
         };
     }
     fn prev_button(&mut self) {
+        // Confirmation has three buttons, so stepping back is not the same as
+        // stepping forward; everything else is a two-way toggle.
+        if let Some(ModalType::Confirmation { .. }) = self.stack.last() {
+            self.active_button = match self.active_button {
+                ModalButton::Confirm => ModalButton::Cancel,
+                ModalButton::ConfirmForce => ModalButton::Confirm,
+                _ => ModalButton::ConfirmForce,
+            };
+            return;
+        }
         self.next_button();
     }
 
@@ -280,6 +370,150 @@ impl ModalManager {
         );
     }
 
+    /// Wrap `text` to at most `width` columns on word boundaries, so a dialog
+    /// can be sized from its content instead of guessing.
+    fn wrap_cols(text: &str, width: u16) -> Vec<String> {
+        let mut lines = Vec::new();
+        let mut current = String::new();
+        for word in text.split_whitespace() {
+            let candidate = if current.is_empty() {
+                word.to_string()
+            } else {
+                format!("{current} {word}")
+            };
+            if fit::cols(&candidate) <= width || current.is_empty() {
+                current = candidate;
+            } else {
+                lines.push(std::mem::take(&mut current));
+                current = word.to_string();
+            }
+        }
+        if !current.is_empty() {
+            lines.push(current);
+        }
+        if lines.is_empty() {
+            lines.push(String::new());
+        }
+        lines
+    }
+
+    /// A centered box just big enough for `message` plus `footer_rows` of
+    /// buttons/hints. Never exceeds the screen, and never gets so narrow that
+    /// the title is clipped.
+    ///
+    /// `min_content_w` is the width the footer needs. Sizing from the message
+    /// alone clipped the key-hint line, which is longer than most questions.
+    fn dialog_rect(area: Rect, message: &str, footer_rows: u16, min_content_w: u16) -> Rect {
+        // 2 border columns + 2 columns of breathing room on each side.
+        const CHROME_W: u16 = 6;
+        const MAX_TEXT_W: u16 = 64;
+        const MIN_TEXT_W: u16 = 24;
+
+        let avail_text = area.width.saturating_sub(CHROME_W).max(1);
+        let text_w = fit::cols(message)
+            .min(MAX_TEXT_W)
+            .min(avail_text)
+            .max(MIN_TEXT_W.min(avail_text));
+        let lines = Self::wrap_cols(message, text_w);
+        let widest = lines
+            .iter()
+            .map(|l| fit::cols(l))
+            .max()
+            .unwrap_or(text_w)
+            .max(min_content_w.min(avail_text));
+
+        let width = (widest + CHROME_W).min(area.width);
+        // borders + blank + message + blank + footer
+        let height = (lines.len() as u16 + footer_rows + 4).min(area.height);
+        Rect {
+            x: area.x + (area.width.saturating_sub(width)) / 2,
+            y: area.y + (area.height.saturating_sub(height)) / 2,
+            width,
+            height,
+        }
+    }
+
+    /// Shared chrome for the small dialogs: themed border, centered message
+    /// with real padding, and the footer row(s) returned for the caller to
+    /// fill with buttons.
+    ///
+    /// The old versions laid their content out over `area` rather than the
+    /// block's inner rect, which put the first line of text on top of the
+    /// border and pushed the buttons against the frame.
+    fn render_dialog_frame(
+        f: &mut Frame,
+        area: Rect,
+        title: &str,
+        message: &str,
+        footer_rows: u16,
+    ) -> Rect {
+        let block = Block::default()
+            .title(
+                Line::from(format!(" {title} ")).style(
+                    Style::default()
+                        .fg(MODAL_TITLE_FG)
+                        .add_modifier(Modifier::BOLD),
+                ),
+            )
+            .borders(Borders::ALL)
+            .border_style(Style::default().fg(MODAL_BORDER_FG))
+            .style(Style::default().bg(MODAL_BG));
+        let inner = block.inner(area);
+        f.render_widget(block, area);
+
+        // Pad one column each side so text never touches the border.
+        let padded = Rect {
+            x: inner.x + 1,
+            y: inner.y,
+            width: inner.width.saturating_sub(2),
+            height: inner.height,
+        };
+        let rows = Layout::default()
+            .direction(Direction::Vertical)
+            .constraints([
+                Constraint::Length(1),           // breathing room under the title
+                Constraint::Min(1),              // message
+                Constraint::Length(1),           // gap above the footer
+                Constraint::Length(footer_rows), // buttons / hints
+            ])
+            .split(padded);
+
+        f.render_widget(
+            Paragraph::new(message)
+                .style(Style::default().fg(MODAL_FG))
+                .alignment(Alignment::Center)
+                .wrap(Wrap { trim: true }),
+            rows[1],
+        );
+        rows[3]
+    }
+
+    /// One button, sized to its label and centered in `area`.
+    fn render_button(f: &mut Frame, area: Rect, label: &str, active: bool, accent: Color) {
+        let style = if active {
+            Style::default()
+                .bg(accent)
+                .fg(MODAL_BG)
+                .add_modifier(Modifier::BOLD)
+        } else {
+            Style::default().fg(accent)
+        };
+        let text = format!(" {label} ");
+        let w = fit::cols(&text).min(area.width);
+        let btn = Rect {
+            x: area.x + (area.width.saturating_sub(w)) / 2,
+            y: area.y,
+            width: w,
+            height: 1,
+        };
+        f.render_widget(
+            Paragraph::new(text)
+                .style(style)
+                .alignment(Alignment::Center),
+            btn,
+        );
+    }
+
     fn render_modal_content(&mut self, f: &mut Frame, modal: &ModalType, data: ProcessModalData) {
         let area = f.area();
         // Different sizes for different modal types
@@ -296,6 +530,13 @@ impl ModalManager {
                 // Help modal uses medium size
                 self.centered_rect(70, 80, area)
             }
+            // Confirmation and Info are one-question dialogs. A fixed 70%x50%
+            // box left a short question floating in a mostly-empty pane, so
+            // these size themselves to their content instead.
+            ModalType::Confirmation { message, .. } => {
+                Self::dialog_rect(area, message, 3, fit::cols(CONFIRM_HINT))
+            }
+            ModalType::Info { message, .. } => Self::dialog_rect(area, message, 1, 16),
             _ => {
                 // Other modals use smaller size
                 self.centered_rect(70, 50, area)
@@ -340,86 +581,64 @@ impl ModalManager {
         confirm_text: &str,
         cancel_text: &str,
     ) {
-        let chunks = Layout::default()
+        // Three buttons + a key hint line.
+        let footer = Self::render_dialog_frame(f, area, title, message, 3);
+        let rows = Layout::default()
             .direction(Direction::Vertical)
-            .constraints([Constraint::Min(1), Constraint::Length(3)])
-            .split(area);
-        let block = Block::default()
-            .title(format!(" {title} "))
-            .borders(Borders::ALL)
-            .style(Style::default().bg(Color::Black));
-        f.render_widget(block, area);
-        f.render_widget(
-            Paragraph::new(message)
-                .style(Style::default().fg(Color::White))
-                .alignment(Alignment::Center)
-                .wrap(Wrap { trim: true }),
-            chunks[0],
-        );
-        let buttons = Layout::default()
+            .constraints([
+                Constraint::Length(1), // buttons
+                Constraint::Length(1), // spacer
+                Constraint::Length(1), // key hints
+            ])
+            .split(footer);
+
+        let cols = Layout::default()
             .direction(Direction::Horizontal)
-            .constraints([Constraint::Percentage(50), Constraint::Percentage(50)])
-            .split(chunks[1]);
-        let confirm_style = if self.active_button == ModalButton::Confirm {
-            Style::default()
-                .bg(Color::Green)
-                .fg(Color::Black)
-                .add_modifier(Modifier::BOLD)
-        } else {
-            Style::default().fg(Color::Green)
-        };
-        let cancel_style = if self.active_button == ModalButton::Cancel {
-            Style::default()
-                .bg(Color::Red)
-                .fg(Color::Black)
-                .add_modifier(Modifier::BOLD)
-        } else {
-            Style::default().fg(Color::Red)
-        };
-        f.render_widget(
-            Paragraph::new(confirm_text)
-                .style(confirm_style)
-                .alignment(Alignment::Center),
-            buttons[0],
+            .constraints([
+                Constraint::Ratio(1, 3),
+                Constraint::Ratio(1, 3),
+                Constraint::Ratio(1, 3),
+            ])
+            .split(rows[0]);
+
+        Self::render_button(
+            f,
+            cols[0],
+            confirm_text,
+            self.active_button == ModalButton::Confirm,
+            BTN_RETRY_BG_ACTIVE,
         );
+        Self::render_button(
+            f,
+            cols[1],
+            "Force kill",
+            self.active_button == ModalButton::ConfirmForce,
+            MODAL_TITLE_FG,
+        );
+        Self::render_button(
+            f,
+            cols[2],
+            cancel_text,
+            self.active_button == ModalButton::Cancel,
+            BTN_EXIT_BG_ACTIVE,
+        );
+
         f.render_widget(
-            Paragraph::new(cancel_text)
-                .style(cancel_style)
+            Paragraph::new(CONFIRM_HINT)
+                .style(Style::default().fg(MODAL_FG).add_modifier(Modifier::DIM))
                 .alignment(Alignment::Center),
-            buttons[1],
+            rows[2],
         );
     }
 
     fn render_info(&self, f: &mut Frame, area: Rect, title: &str, message: &str) {
-        let chunks = Layout::default()
-            .direction(Direction::Vertical)
-            .constraints([Constraint::Min(1), Constraint::Length(3)])
-            .split(area);
-        let block = Block::default()
-            .title(format!(" {title} "))
-            .borders(Borders::ALL)
-            .style(Style::default().bg(Color::Black));
-        f.render_widget(block, area);
-        f.render_widget(
-            Paragraph::new(message)
-                .style(Style::default().fg(Color::White))
-                .alignment(Alignment::Center)
-                .wrap(Wrap { trim: true }),
-            chunks[0],
-        );
-        let ok_style = if self.active_button == ModalButton::Ok {
-            Style::default()
-                .bg(Color::Blue)
-                .fg(Color::White)
-                .add_modifier(Modifier::BOLD)
-        } else {
-            Style::default().fg(Color::Blue)
-        };
-        f.render_widget(
-            Paragraph::new("[ Enter ] OK")
-                .style(ok_style)
-                .alignment(Alignment::Center),
-            chunks[1],
+        let footer = Self::render_dialog_frame(f, area, title, message, 1);
+        Self::render_button(
+            f,
+            footer,
+            "Enter — OK",
+            self.active_button == ModalButton::Ok,
+            BTN_RETRY_BG_ACTIVE,
         );
     }
 
@@ -505,6 +724,9 @@ impl ModalManager {
             "  ↑/↓ ............ Select/navigate processes",
             "  Enter .......... Open Process Details",
             "  x/X ............ Clear selection",
+            "  t .............. Signal selected process — local agent only",
+            "                   (also works inside Process Details; the prompt",
+            "                    offers Terminate/SIGTERM or Force kill/SIGKILL)",
             "  Click header ... Sort by column (CPU/Mem)",
             "  Click row ...... Select process",
             "",
@@ -632,3 +854,254 @@ impl ModalManager {
             .split(vert[1])[1]
     }
 }
+
+#[cfg(test)]
+mod confirm_tests {
+    use super::*;
+
+    fn confirm_modal() -> ModalManager {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::Confirmation {
+            title: "Confirm signal".into(),
+            message: "Send a signal to bash (PID 42)?".into(),
+            confirm_text: "Terminate".into(),
+            cancel_text: "Cancel".into(),
+        });
+        m
+    }
+
+    /// The safe option is focused first, so a reflexive Enter terminates rather
+    /// than force-kills.
+    #[test]
+    fn opens_on_the_safe_option() {
+        let mut m = confirm_modal();
+        assert_eq!(m.active_button, ModalButton::Confirm);
+        assert_eq!(m.handle_key(KeyCode::Enter), ModalAction::Confirm);
+    }
+
+    #[test]
+    fn tab_cycles_all_three_buttons_forward() {
+        let mut m = confirm_modal();
+        m.handle_key(KeyCode::Tab);
+        assert_eq!(m.active_button, ModalButton::ConfirmForce);
+        m.handle_key(KeyCode::Tab);
+        assert_eq!(m.active_button, ModalButton::Cancel);
+        m.handle_key(KeyCode::Tab);
+        assert_eq!(m.active_button, ModalButton::Confirm);
+    }
+
+    /// With three buttons, back is not the same as forward — the old
+    /// prev_button just called next_button, which only worked for two.
+    #[test]
+    fn shift_tab_cycles_backward() {
+        let mut m = confirm_modal();
+        m.handle_key(KeyCode::BackTab);
+        assert_eq!(m.active_button, ModalButton::Cancel);
+        m.handle_key(KeyCode::BackTab);
+        assert_eq!(m.active_button, ModalButton::ConfirmForce);
+        m.handle_key(KeyCode::BackTab);
+        assert_eq!(m.active_button, ModalButton::Confirm);
+    }
+
+    #[test]
+    fn force_kill_reports_its_own_action() {
+        let mut m = confirm_modal();
+        m.handle_key(KeyCode::Tab);
+        assert_eq!(m.handle_key(KeyCode::Enter), ModalAction::ConfirmForce);
+    }
+
+    #[test]
+    fn escape_cancels_and_closes() {
+        let mut m = confirm_modal();
+        assert_eq!(m.handle_key(KeyCode::Esc), ModalAction::Cancel);
+        assert!(!m.is_active());
+    }
+
+    /// Enter on Cancel must behave like Esc, including closing the modal.
+    #[test]
+    fn enter_on_cancel_closes_too() {
+        let mut m = confirm_modal();
+        m.handle_key(KeyCode::Tab);
+        m.handle_key(KeyCode::Tab);
+        assert_eq!(m.handle_key(KeyCode::Enter), ModalAction::Cancel);
+        assert!(!m.is_active());
+    }
+
+    /// `t` inside process details asks the app to raise the kill prompt for the
+    /// process being viewed — not for whatever is selected in the list behind it.
+    #[test]
+    fn t_in_process_details_targets_that_pid() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 4242 });
+        assert_eq!(
+            m.handle_key(KeyCode::Char('t')),
+            ModalAction::KillSelected(4242)
+        );
+    }
+
+    /// `k` still scrolls the thread table, which is why `t` is the kill key.
+    #[test]
+    fn k_in_process_details_still_scrolls() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 1 });
+        m.thread_scroll_max = 5;
+        m.handle_key(KeyCode::Char('j'));
+        assert_eq!(m.thread_scroll_offset, 1);
+        assert_eq!(m.handle_key(KeyCode::Char('k')), ModalAction::Handled);
+        assert_eq!(m.thread_scroll_offset, 0);
+    }
+
+    #[test]
+    fn t_elsewhere_is_not_a_kill() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::Help);
+        assert_eq!(m.handle_key(KeyCode::Char('t')), ModalAction::None);
+    }
+
+    /// A one-line question must not be handed a half-screen box.
+    #[test]
+    fn dialog_is_sized_to_its_content() {
+        let screen = Rect::new(0, 0, 120, 40);
+        let r = ModalManager::dialog_rect(
+            screen,
+            "Send a signal to bash (PID 42)?",
+            3,
+            fit::cols(CONFIRM_HINT),
+        );
+        assert!(r.width < screen.width, "dialog took the full width");
+        assert!(r.height <= 12, "dialog was {} rows tall", r.height);
+        assert!(r.height >= 7, "dialog too short to hold its own footer");
+        // Centered to within the rounding of integer division.
+        let center_delta = (r.x + r.width / 2) as i32 - (screen.width / 2) as i32;
+        assert!(center_delta.abs() <= 1, "off-center by {center_delta}");
+    }
+
+    #[test]
+    fn dialog_never_exceeds_a_small_screen() {
+        let screen = Rect::new(0, 0, 20, 8);
+        let long = "a".repeat(400);
+        let r = ModalManager::dialog_rect(screen, &long, 3, fit::cols(CONFIRM_HINT));
+        assert!(r.width <= screen.width && r.height <= screen.height);
+    }
+}
+
+#[cfg(test)]
+mod button_style_tests {
+    use super::*;
+    use ratatui::Terminal;
+    use ratatui::backend::TestBackend;
+
+    /// The focused button must be the highlighted one — the whole point of the
+    /// three-button layout is that you can see which action Enter will run.
+    #[test]
+    fn focus_moves_the_highlight() {
+        let msg = "Send a signal to bash (PID 42)?";
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::Confirmation {
+            title: "Confirm signal".into(),
+            message: msg.into(),
+            confirm_text: "Terminate".into(),
+            cancel_text: "Cancel".into(),
+        });
+
+        // Background colors present on the button row, per focused button.
+        let bgs = |m: &ModalManager| -> Vec<Color> {
+            let screen = Rect::new(0, 0, 100, 30);
+            let area = ModalManager::dialog_rect(screen, msg, 3, fit::cols(CONFIRM_HINT));
+            let mut t = Terminal::new(TestBackend::new(100, 30)).unwrap();
+            t.draw(|f| {
+                m.render_confirmation(f, area, "Confirm signal", msg, "Terminate", "Cancel")
+            })
+            .unwrap();
+            let buf = t.backend().buffer();
+            // Buttons sit on the first footer row: title, gap, message, gap.
+            let row = area.y + 4;
+            (area.x..area.x + area.width)
+                .map(|x| buf[(x, row)].bg)
+                .collect()
+        };
+
+        let terminate_focused = bgs(&m);
+        assert!(
+            terminate_focused.contains(&BTN_RETRY_BG_ACTIVE),
+            "Terminate should be highlighted when focused"
+        );
+        assert!(
+            !terminate_focused.contains(&BTN_EXIT_BG_ACTIVE),
+            "Cancel must not be highlighted while Terminate has focus"
+        );
+
+        m.handle_key(KeyCode::Tab);
+        m.handle_key(KeyCode::Tab);
+        let cancel_focused = bgs(&m);
+        assert!(
+            cancel_focused.contains(&BTN_EXIT_BG_ACTIVE),
+            "Cancel should be highlighted after two Tabs"
+        );
+        assert!(
+            !cancel_focused.contains(&BTN_RETRY_BG_ACTIVE),
+            "Terminate must not stay highlighted"
+        );
+    }
+}
+
+#[cfg(test)]
+mod close_details_tests {
+    use super::*;
+
+    #[test]
+    fn closes_the_view_for_that_pid() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 4242 });
+        assert!(m.close_process_details(4242));
+        assert!(!m.is_active());
+    }
+
+    #[test]
+    fn leaves_a_different_pid_alone() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 4242 });
+        assert!(!m.close_process_details(1));
+        assert!(m.is_active());
+    }
+
+    /// Walking up to a parent stacks details views. Only the dead process's
+    /// view goes — whichever position it holds — and the survivor stays put.
+    #[test]
+    fn closes_only_the_dead_pids_view_in_a_parent_chain() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 100 }); // parent
+        m.push_modal(ModalType::ProcessDetails { pid: 200 }); // child, on top
+
+        // Parent dies while the child is viewed: its view is removed from
+        // UNDER the top, so closing the child later lands on the process list
+        // instead of a frozen corpse view.
+        assert!(m.close_process_details(100));
+        assert!(matches!(
+            m.current_modal(),
+            Some(ModalType::ProcessDetails { pid: 200 })
+        ));
+        assert!(m.close_process_details(200));
+        assert!(!m.is_active());
+    }
+
+    /// The F1 regression: killing from inside the details view stacks the
+    /// "Signal sent" Info on top, and the death is usually confirmed while
+    /// that Info is still up. The details view must close anyway — a top-only
+    /// check left it open forever, frozen on the dead process.
+    #[test]
+    fn closes_details_beneath_a_stacked_info_modal() {
+        let mut m = ModalManager::new();
+        m.push_modal(ModalType::ProcessDetails { pid: 7 });
+        m.push_modal(ModalType::Info {
+            title: "Signal sent".into(),
+            message: "Sent SIGKILL".into(),
+        });
+
+        assert!(m.close_process_details(7));
+        // The Info survives on top; dismissing it lands on the process list.
+        assert!(matches!(m.current_modal(), Some(ModalType::Info { .. })));
+        m.pop_modal();
+        assert!(!m.is_active());
+    }
+}

socktop/src/ui/modal_connection.rs

@@ -41,11 +41,12 @@ impl ModalManager {
             ])
             .split(area);
         let block = Block::default()
-            .title(ICON_WARNING_TITLE)
-            .title_style(
-                Style::default()
-                    .fg(MODAL_TITLE_FG)
-                    .add_modifier(Modifier::BOLD),
+            .title(
+                Line::from(ICON_WARNING_TITLE).style(
+                    Style::default()
+                        .fg(MODAL_TITLE_FG)
+                        .add_modifier(Modifier::BOLD),
+                ),
             )
             .borders(Borders::ALL)
             .border_style(Style::default().fg(MODAL_BORDER_FG))

socktop/src/ui/modal_process.rs

@@ -60,6 +60,7 @@ impl ModalManager {
                 main_chunks[0],
                 &details.process,
                 data.history.cpu,
+                data.history.cpu_sum,
             );
 
             // Middle Row: Memory/IO + Thread Table + Command Details (with process metadata)
@@ -94,7 +95,7 @@ impl ModalManager {
         }
 
         // Help line
-        let help_text = vec![Line::from(vec![
+        let mut help_text = vec![Line::from(vec![
             Span::styled(
                 "X ",
                 Style::default()
@@ -128,6 +129,23 @@ impl ModalManager {
             Span::styled("journal", Style::default().add_modifier(Modifier::DIM)),
         ])];
 
+        // Kill from here too — same key as the processes pane, and only shown
+        // when the agent is local, since that is the only case where it works.
+        if data.is_local
+            && let Some(line) = help_text.first_mut()
+        {
+            line.spans.push(Span::styled(
+                "  t ",
+                Style::default()
+                    .fg(PROCESS_DETAILS_ACCENT)
+                    .add_modifier(Modifier::BOLD),
+            ));
+            line.spans.push(Span::styled(
+                "kill",
+                Style::default().add_modifier(Modifier::DIM),
+            ));
+        }
+
         let help = Paragraph::new(Text::from(help_text))
             .alignment(Alignment::Center)
             .style(Style::default());
@@ -419,7 +437,7 @@ impl ModalManager {
         )
         .header(header)
         .block(block)
-        .highlight_style(Style::default());
+        .row_highlight_style(Style::default());
 
         f.render_widget(table, area);
 
@@ -471,13 +489,28 @@ impl ModalManager {
             .borders(Borders::ALL);
 
         let content_lines: Vec<Line> = if journal.entries.is_empty() {
-            vec![
+            let mut lines = vec![
                 Line::from(""),
                 Line::from(Span::styled(
                     "No journal entries found for this process",
                     Style::default().add_modifier(Modifier::DIM),
                 )),
-            ]
+            ];
+            // Access limits, not absence of logs: show journalctl's own hint
+            // (typical when the agent runs as an unprivileged user, e.g. demo
+            // mode) plus the practical fix.
+            if let Some(notice) = &journal.notice {
+                lines.push(Line::from(""));
+                lines.push(Line::from(Span::styled(
+                    format!("⚠ {notice}"),
+                    Style::default().fg(Color::Yellow),
+                )));
+                lines.push(Line::from(Span::styled(
+                    "  Run the agent as a service (or a user in the systemd-journal group) for full journal access.",
+                    Style::default().add_modifier(Modifier::DIM),
+                )));
+            }
+            lines
         } else {
             journal
                 .entries
@@ -564,8 +597,13 @@ impl ModalManager {
             return;
         }
 
-        // Create a 2D grid to represent the plot
-        let mut plot_grid = vec![vec![' '; plot_width]; plot_height];
+        // Flat plot grid indexed as grid[y * plot_width + x]. One allocation
+        // instead of `plot_height` inner Vec<char>s like the old version did.
+        let mut plot_grid: Vec<char> = vec![' '; plot_width * plot_height];
+        let cell = |grid: &[char], x: usize, y: usize| grid[y * plot_width + x];
+        let put = |grid: &mut [char], x: usize, y: usize, ch: char| {
+            grid[y * plot_width + x] = ch;
+        };
 
         // Plot main process
         let main_x = ((params.main_user_ms / params.max_user) * (plot_width - 1) as f64) as usize;
@@ -573,7 +611,7 @@ impl ModalManager {
             ((params.main_system_ms / params.max_system) * (plot_height - 1) as f64) as usize,
         );
         if main_x < plot_width && main_y < plot_height {
-            plot_grid[main_y][main_x] = '●'; // Main process marker
+            put(&mut plot_grid, main_x, main_y, '●');
         }
 
         // Plot threads (use different marker)
@@ -587,13 +625,13 @@ impl ModalManager {
             );
 
             if thread_x < plot_width && thread_y < plot_height {
-                if plot_grid[thread_y][thread_x] == ' ' {
-                    plot_grid[thread_y][thread_x] = '○'; // Thread marker (hollow circle)
-                } else if plot_grid[thread_y][thread_x] == '○' {
-                    plot_grid[thread_y][thread_x] = '◎'; // Multiple threads at same point
-                } else {
-                    plot_grid[thread_y][thread_x] = '◉'; // Mixed threads/processes at same point
-                }
+                let ch = cell(&plot_grid, thread_x, thread_y);
+                let next = match ch {
+                    ' ' => '○',
+                    '○' => '◎',
+                    _ => '◉',
+                };
+                put(&mut plot_grid, thread_x, thread_y, next);
             }
         }
 
@@ -608,28 +646,47 @@ impl ModalManager {
             );
 
             if child_x < plot_width && child_y < plot_height {
-                if plot_grid[child_y][child_x] == ' ' {
-                    plot_grid[child_y][child_x] = '•'; // Child process marker
-                } else {
-                    plot_grid[child_y][child_x] = '◉'; // Multiple items at same point
-                }
+                let ch = cell(&plot_grid, child_x, child_y);
+                let next = if ch == ' ' { '•' } else { '◉' };
+                put(&mut plot_grid, child_x, child_y, next);
             }
         }
 
-        // Render the plot
-        let mut lines = Vec::new();
+        // Build the rendered lines. Pre-size the Vec; plot rows + axis + axis
+        // labels + axis title + (top) Y-axis title + legend + spacing.
+        let mut lines: Vec<Line> = Vec::with_capacity(plot_height + 6);
 
-        // Add Y-axis labels and plot content
-        for (i, row) in plot_grid.iter().enumerate() {
-            let y_value = params.max_system * (1.0 - (i as f64 / (plot_height - 1) as f64));
-            // Always format with 4 characters width, right-aligned, to prevent axis shifting
-            let y_label = if y_value >= 100.0 {
-                format!("{y_value:>4.0}")
+        // Format a CPU-time value: whole ms once past 100, one decimal below.
+        let fmt_ms = |v: f64| {
+            if v >= 100.0 {
+                format!("{v:.0}")
             } else {
-                format!("{y_value:>4.1}")
-            };
+                format!("{v:.1}")
+            }
+        };
 
-            let plot_content: String = row.iter().collect();
+        // Y-axis labels, right-aligned to the widest value this frame so the
+        // axis stays a straight line. The old fixed 4-char field predates the
+        // CPU-time unit fix; honest millisecond values (e.g. 136114) blew
+        // through it and skewed the whole axis.
+        let y_values: Vec<String> = (0..plot_height)
+            .map(|y| {
+                fmt_ms(params.max_system * (1.0 - (y as f64 / (plot_height - 1).max(1) as f64)))
+            })
+            .collect();
+        let y_label_w = y_values.iter().map(|s| s.len()).max().unwrap_or(4).max(4);
+
+        let mut row_buf = String::with_capacity(plot_width);
+        for (y, y_value) in y_values.iter().enumerate() {
+            let y_label = format!("{y_value:>y_label_w$}");
+
+            // Build the row's char slice into a reusable String buffer.
+            row_buf.clear();
+            let start = y * plot_width;
+            row_buf.extend(plot_grid[start..start + plot_width].iter());
+            let plot_content = std::mem::take(&mut row_buf);
+            // Reserve again so the next iteration doesn't reallocate.
+            row_buf.reserve(plot_width);
 
             lines.push(Line::from(vec![
                 Span::styled(y_label, Style::default()),
@@ -638,8 +695,8 @@ impl ModalManager {
             ]));
         }
 
-        // Add X-axis
-        let x_axis_padding = "     ".to_string(); // Match Y-axis label width
+        // Add X-axis (padding = Y label width + the space before the bar)
+        let x_axis_padding = " ".repeat(y_label_w + 1);
         let x_axis_line = "─".repeat(plot_width + 1);
         lines.push(Line::from(vec![
             Span::styled(x_axis_padding, Style::default()),
@@ -647,13 +704,14 @@ impl ModalManager {
         ]));
 
         // Add X-axis labels
-        let x_label_start = "0.0".to_string();
-        let x_label_mid = format!("{:.1}", params.max_user / 2.0);
-        let x_label_end = format!("{:.1}", params.max_user);
+        let x_label_start = fmt_ms(0.0);
+        let x_label_mid = fmt_ms(params.max_user / 2.0);
+        let x_label_end = fmt_ms(params.max_user);
 
         let spacing = plot_width / 3;
         let x_labels = format!(
-            "     {}{}{}{}{}",
+            "{}{}{}{}{}{}",
+            " ".repeat(y_label_w + 1),
             x_label_start,
             " ".repeat(spacing.saturating_sub(x_label_start.len())),
             x_label_mid,
@@ -665,7 +723,7 @@ impl ModalManager {
 
         // Add axis titles with better visibility
         lines.push(Line::from(vec![Span::styled(
-            "     User CPU Time (ms) →",
+            format!("{}User CPU Time (ms) →", " ".repeat(y_label_w + 1)),
             Style::default()
                 .fg(Color::Yellow)
                 .add_modifier(Modifier::BOLD),
@@ -833,6 +891,7 @@ impl ModalManager {
         area: Rect,
         process: &socktop_connector::DetailedProcessInfo,
         cpu_history: &std::collections::VecDeque<f32>,
+        cpu_history_sum: f32,
     ) {
         // Split top row: CPU sparkline (left 60%) | Thread scatter plot (right 40%)
         let top_chunks = Layout::default()
@@ -843,7 +902,7 @@ impl ModalManager {
             ])
             .split(area);
 
-        self.render_cpu_sparkline(f, top_chunks[0], process, cpu_history);
+        self.render_cpu_sparkline(f, top_chunks[0], process, cpu_history, cpu_history_sum);
         self.render_thread_scatter_plot(f, top_chunks[1], process);
     }
 
@@ -853,6 +912,7 @@ impl ModalManager {
         area: Rect,
         process: &socktop_connector::DetailedProcessInfo,
         cpu_history: &std::collections::VecDeque<f32>,
+        cpu_history_sum: f32,
     ) {
         // Normalize CPU to 0-100% by dividing by thread count
         // This shows per-core utilization rather than total utilization across all cores
@@ -864,8 +924,7 @@ impl ModalManager {
         let avg_cpu = if cpu_history.is_empty() {
             0.0
         } else {
-            let total: f32 = cpu_history.iter().sum();
-            normalize_cpu_usage(total / cpu_history.len() as f32, thread_count)
+            normalize_cpu_usage(cpu_history_sum / cpu_history.len() as f32, thread_count)
         };
         let title = format!("CPU (now: {current_cpu:.1}% | {avg_cpu:.1}%)");
 

socktop/src/ui/modal_types.rs

@@ -5,6 +5,8 @@ use std::time::Instant;
 /// History data for process metrics rendering
 pub struct ProcessHistoryData<'a> {
     pub cpu: &'a std::collections::VecDeque<f32>,
+    /// Running sum of `cpu` maintained by the caller (avoids re-summing per frame)
+    pub cpu_sum: f32,
     pub mem: &'a std::collections::VecDeque<u64>,
     pub io_read: &'a std::collections::VecDeque<u64>,
     pub io_write: &'a std::collections::VecDeque<u64>,
@@ -17,6 +19,9 @@ pub struct ProcessModalData<'a> {
     pub history: ProcessHistoryData<'a>,
     pub max_mem_bytes: u64,
     pub unsupported: bool,
+    /// Whether the agent is on this machine. Only used to decide whether the
+    /// `t` kill hint is shown — the kill itself is gated in `App`.
+    pub is_local: bool,
 }
 
 /// Parameters for rendering scatter plot
@@ -62,9 +67,15 @@ pub enum ModalAction {
     RetryConnection,
     ExitApp,
     Confirm,
+    /// Confirmation modal's second affirmative: the same action, escalated.
+    /// Used by the kill prompt for SIGKILL, where `Confirm` means SIGTERM.
+    ConfirmForce,
     Cancel,
     Dismiss,
     SwitchToParentProcess(u32), // Switch to viewing parent process details
+    /// `t` pressed while viewing a process's details — the app decides whether
+    /// the agent is local and, if so, raises the kill confirmation.
+    KillSelected(u32),
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -72,6 +83,10 @@ pub enum ModalButton {
     Retry,
     Exit,
     Confirm,
+    /// Escalated affirmative on a Confirmation modal (SIGKILL for the kill
+    /// prompt). Separate button rather than a separate keybinding so the
+    /// destructive option has to be selected deliberately.
+    ConfirmForce,
     Cancel,
     Ok,
 }

socktop/src/ui/net.rs

@@ -11,12 +11,12 @@ pub fn draw_net_spark(
     f: &mut ratatui::Frame<'_>,
     area: Rect,
     title: &str,
-    hist: &VecDeque<u64>,
+    hist: &mut VecDeque<u64>,
     color: Color,
 ) {
     let max_points = area.width.saturating_sub(2) as usize;
     let start = hist.len().saturating_sub(max_points);
-    let data: Vec<u64> = hist.iter().skip(start).cloned().collect();
+    let slice = &hist.make_contiguous()[start..];
 
     let spark = Sparkline::default()
         .block(
@@ -24,7 +24,7 @@ pub fn draw_net_spark(
                 .borders(Borders::ALL)
                 .title(title.to_string()),
         )
-        .data(&data)
+        .data(slice)
         .style(Style::default().fg(color));
     f.render_widget(spark, area);
 }

socktop/src/ui/util.rs

@@ -22,19 +22,6 @@ pub fn human(b: u64) -> String {
     format!("{tb:.2}TB")
 }
 
-pub fn truncate_middle(s: &str, max: usize) -> String {
-    if s.len() <= max {
-        return s.to_string();
-    }
-    if max <= 3 {
-        return "...".into();
-    }
-    let keep = max - 3;
-    let left = keep / 2;
-    let right = keep - left;
-    format!("{}...{}", &s[..left], &s[s.len() - right..])
-}
-
 pub fn disk_icon(name: &str) -> &'static str {
     let n = name.to_ascii_lowercase();
     if n.contains(':') {

socktop/tests/cli_args.rs

@@ -73,3 +73,36 @@ fn test_tlc_ca_arg_long_and_short_parsed() {
     );
     assert!(text3.contains("Usage:"));
 }
+
+#[test]
+fn test_compact_flag_documented_and_accepted() {
+    let exe = env!("CARGO_BIN_EXE_socktop");
+    let out = Command::new(exe)
+        .args(["--compact", "--help"])
+        .output()
+        .expect("run socktop --compact --help");
+    assert!(
+        out.status.success(),
+        "socktop --compact --help did not succeed"
+    );
+    let text = format!(
+        "{}{}",
+        String::from_utf8_lossy(&out.stdout),
+        String::from_utf8_lossy(&out.stderr)
+    );
+    assert!(
+        text.contains("--compact"),
+        "help text missing --compact\n{text}"
+    );
+
+    // The flag must not be mistaken for the positional URL argument.
+    let out2 = Command::new(exe)
+        .args(["--compact", "--dry-run", "ws://127.0.0.1:3000/ws"])
+        .output()
+        .expect("run socktop --compact --dry-run");
+    assert!(
+        out2.status.success(),
+        "socktop --compact with a URL was rejected: {}",
+        String::from_utf8_lossy(&out2.stderr)
+    );
+}

socktop/tests/profiles.rs

@@ -8,6 +8,7 @@ static ENV_LOCK: Mutex<()> = Mutex::new(());
 #[allow(dead_code)] // touch crate
 fn touch() {
     let _ = socktop::types::Metrics {
+        sampled_at_ms: None,
         cpu_total: 0.0,
         cpu_per_core: vec![],
         mem_total: 0,

socktop_agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "socktop_agent"
-version = "1.50.2"
+version = "1.60.0"
 authors = ["Jason Witty <jasonpwitty+socktop@proton.me>"]
 description = "Socktop agent daemon. Serves host metrics over WebSocket."
 edition = "2024"
@@ -10,11 +10,10 @@ homepage = "https://github.com/jasonwitty/socktop"
 repository = "https://github.com/jasonwitty/socktop"
 
 [dependencies]
-# Tokio: Use minimal features instead of "full" to reduce binary size
-# Only include: rt-multi-thread (async runtime), net (WebSocket), sync (Mutex/RwLock), macros (#[tokio::test])
-# Excluded: io, fs, process, signal, time (not needed for this workload)
-# Savings: ~200-300KB binary size, faster compile times
-tokio = { version = "1", features = ["rt-multi-thread", "net", "sync", "macros"] }
+# Tokio: minimal features instead of "full" to reduce binary size.
+# rt-multi-thread (runtime), net (WebSocket), sync (Mutex/oneshot),
+# macros (#[tokio::test]), process (async journalctl).
+tokio = { version = "1", features = ["rt-multi-thread", "net", "sync", "macros", "process"] }
 axum = { version = "0.7", features = ["ws", "macros"] }
 sysinfo = { version = "0.37", features = ["network", "disk", "component"] }
 serde = { version = "1", features = ["derive"] }
@@ -24,6 +23,10 @@ futures-util = "0.3.31"
 tracing = { version = "0.1", optional = true }
 tracing-subscriber = { version = "0.3", features = ["env-filter"], optional = true }
 gfxinfo = { version = "0.1.2", optional = true }
+# Direct NVML fallback for distros that ship only libnvidia-ml.so.1 (Debian
+# and derivatives) — gfxinfo's default init dlopens the unversioned name.
+# Same version gfxinfo already pulls in, so this adds no new build cost.
+nvml-wrapper = { version = "0.10", optional = true }
 once_cell = "1.19"
 axum-server = { version = "0.7", features = ["tls-rustls"] }
 rustls = { version = "0.23", features = ["aws-lc-rs"] }
@@ -36,7 +39,7 @@ time = { version = "0.3", default-features = false, features = ["formatting", "m
 
 [features]
 default = ["gpu"]
-gpu = ["gfxinfo"]
+gpu = ["gfxinfo", "nvml-wrapper"]
 logging = ["tracing", "tracing-subscriber"]
 
 [build-dependencies]

socktop_agent/build.rs

@@ -1,13 +1,15 @@
 fn main() {
-    // Vendored protoc for reproducible builds
-    let protoc = protoc_bin_vendored::protoc_bin_path().expect("protoc");
-
     println!("cargo:rerun-if-changed=proto/processes.proto");
 
     // Compile protobuf definitions for processes
     let mut cfg = prost_build::Config::new();
     cfg.out_dir(std::env::var("OUT_DIR").unwrap());
-    cfg.protoc_executable(protoc); // Use the vendored protoc directly
+    // Vendored protoc for reproducible builds where available. It ships no
+    // riscv64 binary, so on such hosts fall through to $PROTOC / PATH
+    // (prost-build's default lookup) — apt: protobuf-compiler.
+    if let Ok(protoc) = protoc_bin_vendored::protoc_bin_path() {
+        cfg.protoc_executable(protoc);
+    }
     // Use local path (ensures file is inside published crate tarball)
     cfg.compile_protos(&["proto/processes.proto"], &["proto"]) // relative to CARGO_MANIFEST_DIR
         .expect("compile protos");

socktop_agent/debian/postinst

@@ -29,27 +29,27 @@ cat <<EOF
 ┌─────────────────────────────────────────────────────────────────────┐
 │ socktop-agent has been installed successfully!                      │
 ├─────────────────────────────────────────────────────────────────────┤
-│                                                                     │
-│ The systemd service has been installed but is NOT enabled by       │
-│ default. To enable and start the service:                          │
-│                                                                     │
-│   sudo systemctl enable --now socktop-agent                        │
-│                                                                     │
-│ To start without enabling on boot:                                 │
-│                                                                     │
-│   sudo systemctl start socktop-agent                               │
-│                                                                     │
-│ To check service status:                                           │
-│                                                                     │
-│   sudo systemctl status socktop-agent                              │
-│                                                                     │
-│ Default settings:                                                  │
-│   - Port: 3000 (use -p or --port to change)                       │
-│   - SSL/TLS: disabled (use --enableSSL to enable)                 │
-│                                                                     │
-│ For more information, see:                                         │
-│   /usr/share/doc/socktop_agent/README.md                           │
-│                                                                     │
+│                                                                      │
+│ The systemd service has been installed but is NOT enabled by        │
+│ default. To enable and start the service:                           │
+│                                                                      │
+│   sudo systemctl enable --now socktop-agent                         │
+│                                                                      │
+│ To start without enabling on boot:                                  │
+│                                                                      │
+│   sudo systemctl start socktop-agent                                │
+│                                                                      │
+│ To check service status:                                            │
+│                                                                      │
+│   sudo systemctl status socktop-agent                               │
+│                                                                      │
+│ Default settings:                                                   │
+│   - Port: 3000 (use -p or --port to change)                        │
+│   - SSL/TLS: disabled (use --enableSSL to enable)                  │
+│                                                                      │
+│ For more information, see:                                          │
+│   /usr/share/doc/socktop_agent/README.md                            │
+│                                                                      │
 └─────────────────────────────────────────────────────────────────────┘
 
 EOF

socktop_agent/src/cache.rs

@@ -1,95 +0,0 @@
-//! Caching for process metrics and journal entries
-
-use std::collections::HashMap;
-use std::time::{Duration, Instant};
-use tokio::sync::RwLock;
-
-use crate::types::{ProcessMetricsResponse, JournalResponse};
-
-#[derive(Debug, Clone)]
-struct CacheEntry<T> {
-    data: T,
-    cached_at: Instant,
-    ttl: Duration,
-}
-
-impl<T> CacheEntry<T> {
-    fn is_expired(&self) -> bool {
-        self.cached_at.elapsed() > self.ttl
-    }
-}
-
-#[derive(Debug)]
-pub struct ProcessCache {
-    process_metrics: RwLock<HashMap<u32, CacheEntry<ProcessMetricsResponse>>>,
-    journal_entries: RwLock<HashMap<u32, CacheEntry<JournalResponse>>>,
-}
-
-impl ProcessCache {
-    pub fn new() -> Self {
-        Self {
-            process_metrics: RwLock::new(HashMap::new()),
-            journal_entries: RwLock::new(HashMap::new()),
-        }
-    }
-
-    /// Get cached process metrics if available and not expired (250ms TTL)
-    pub async fn get_process_metrics(&self, pid: u32) -> Option<ProcessMetricsResponse> {
-        let cache = self.process_metrics.read().await;
-        if let Some(entry) = cache.get(&pid) {
-            if !entry.is_expired() {
-                return Some(entry.data.clone());
-            }
-        }
-        None
-    }
-
-    /// Cache process metrics with 250ms TTL
-    pub async fn set_process_metrics(&self, pid: u32, data: ProcessMetricsResponse) {
-        let mut cache = self.process_metrics.write().await;
-        cache.insert(pid, CacheEntry {
-            data,
-            cached_at: Instant::now(),
-            ttl: Duration::from_millis(250),
-        });
-    }
-
-    /// Get cached journal entries if available and not expired (1s TTL)
-    pub async fn get_journal_entries(&self, pid: u32) -> Option<JournalResponse> {
-        let cache = self.journal_entries.read().await;
-        if let Some(entry) = cache.get(&pid) {
-            if !entry.is_expired() {
-                return Some(entry.data.clone());
-            }
-        }
-        None
-    }
-
-    /// Cache journal entries with 1s TTL
-    pub async fn set_journal_entries(&self, pid: u32, data: JournalResponse) {
-        let mut cache = self.journal_entries.write().await;
-        cache.insert(pid, CacheEntry {
-            data,
-            cached_at: Instant::now(),
-            ttl: Duration::from_secs(1),
-        });
-    }
-
-    /// Clean up expired entries periodically
-    pub async fn cleanup_expired(&self) {
-        {
-            let mut cache = self.process_metrics.write().await;
-            cache.retain(|_, entry| !entry.is_expired());
-        }
-        {
-            let mut cache = self.journal_entries.write().await;
-            cache.retain(|_, entry| !entry.is_expired());
-        }
-    }
-}
-
-impl Default for ProcessCache {
-    fn default() -> Self {
-        Self::new()
-    }
-}

socktop_agent/src/gpu.rs

@@ -1,6 +1,4 @@
 // gpu.rs
-#[cfg(feature = "gpu")]
-use gfxinfo::active_gpu;
 
 #[derive(Debug, Clone, serde::Serialize)]
 pub struct GpuMetrics {
@@ -10,23 +8,118 @@ pub struct GpuMetrics {
     pub mem_total_bytes: u64,
 }
 
+/// Collect metrics for the active GPU. `None` when there is no usable GPU.
+///
+/// Runs on a dedicated worker thread (see `worker`): gfxinfo's handle holds
+/// an `Rc<Nvml>` (not `Send`), and *creating* it runs a full NVML library
+/// init — ~20ms of blocking work that used to execute on the async runtime
+/// for every collection. The worker owns one handle for the process lifetime,
+/// so steady-state collection is just NVML queries. Measured on an RTX 5080
+/// box, re-initing per collect was ~80% of the agent's entire active CPU.
 #[cfg(feature = "gpu")]
-pub fn collect_all_gpus() -> Result<Vec<GpuMetrics>, Box<dyn std::error::Error>> {
-    let gpu = active_gpu()?; // Use ? to unwrap Result
-    let info = gpu.info();
-
-    let metrics = GpuMetrics {
-        name: gpu.model().to_string(),
-        utilization_gpu_pct: info.load_pct() as u32,
-        mem_used_bytes: info.used_vram(),
-        mem_total_bytes: info.total_vram(),
-    };
-
-    Ok(vec![metrics])
+pub async fn collect_all_gpus() -> Option<Vec<GpuMetrics>> {
+    worker::collect().await
 }
 
 #[cfg(not(feature = "gpu"))]
-pub fn collect_all_gpus() -> Result<Vec<GpuMetrics>, Box<dyn std::error::Error>> {
-    // GPU support not available on this platform
-    Ok(vec![])
+pub async fn collect_all_gpus() -> Option<Vec<GpuMetrics>> {
+    None
+}
+
+#[cfg(feature = "gpu")]
+mod worker {
+    use super::GpuMetrics;
+    use once_cell::sync::OnceCell;
+    use std::sync::mpsc;
+
+    type Reply = tokio::sync::oneshot::Sender<Option<Vec<GpuMetrics>>>;
+    static TX: OnceCell<mpsc::Sender<Reply>> = OnceCell::new();
+
+    pub async fn collect() -> Option<Vec<GpuMetrics>> {
+        let tx = TX.get_or_init(spawn);
+        let (reply_tx, reply_rx) = tokio::sync::oneshot::channel();
+        tx.send(reply_tx).ok()?;
+        reply_rx.await.ok().flatten()
+    }
+
+    fn spawn() -> mpsc::Sender<Reply> {
+        let (tx, rx) = mpsc::channel::<Reply>();
+        std::thread::Builder::new()
+            .name("socktop-gpu".into())
+            .spawn(move || run(rx))
+            .expect("spawn gpu worker thread");
+        tx
+    }
+
+    enum Handle {
+        /// gfxinfo's own detection (AMD sysfs, NVIDIA via unversioned NVML).
+        Gfx(Box<dyn gfxinfo::Gpu>),
+        /// Direct NVML with an explicit versioned soname. Debian & friends
+        /// ship only libnvidia-ml.so.1 (the unversioned symlink lives in the
+        /// dev package), so gfxinfo's default dlopen fails there even though
+        /// the driver is fully functional.
+        Nvml(Box<nvml_wrapper::Nvml>),
+    }
+
+    fn probe() -> Option<Handle> {
+        if let Ok(g) = gfxinfo::active_gpu() {
+            return Some(Handle::Gfx(g));
+        }
+        nvml_wrapper::Nvml::builder()
+            .lib_path(std::ffi::OsStr::new("libnvidia-ml.so.1"))
+            .init()
+            .ok()
+            .map(|nvml| Handle::Nvml(Box::new(nvml)))
+    }
+
+    fn collect_from(handle: &Handle) -> Option<Vec<GpuMetrics>> {
+        match handle {
+            Handle::Gfx(gpu) => {
+                let info = gpu.info();
+                Some(vec![GpuMetrics {
+                    name: gpu.model().to_string(),
+                    utilization_gpu_pct: info.load_pct().clamp(0, 100),
+                    mem_used_bytes: info.used_vram(),
+                    mem_total_bytes: info.total_vram(),
+                }])
+            }
+            Handle::Nvml(nvml) => {
+                let device = nvml.device_by_index(0).ok()?;
+                let mem = device.memory_info().ok()?;
+                Some(vec![GpuMetrics {
+                    name: device.name().unwrap_or_else(|_| "NVIDIA GPU".into()),
+                    utilization_gpu_pct: device
+                        .utilization_rates()
+                        .map(|u| u.gpu.clamp(0, 100))
+                        .unwrap_or(0),
+                    mem_used_bytes: mem.used,
+                    mem_total_bytes: mem.total,
+                }])
+            }
+        }
+    }
+
+    fn run(rx: mpsc::Receiver<Reply>) {
+        let mut handle: Option<Handle> = None;
+        // Probing failed: remember and answer None without re-initing the GPU
+        // stack per request. The agent's negative cache stops asking anyway.
+        let mut probe_failed = false;
+        while let Ok(reply) = rx.recv() {
+            if handle.is_none() && !probe_failed {
+                handle = probe();
+                probe_failed = handle.is_none();
+            }
+            let out = handle.as_ref().and_then(collect_from);
+            // A live GPU cannot report 0 total VRAM; zeros mean the session
+            // died (e.g. driver reload). Drop the handle so the next request
+            // re-probes.
+            if let Some(v) = &out
+                && !v.is_empty()
+                && v.iter().all(|g| g.mem_total_bytes == 0)
+            {
+                handle = None;
+            }
+            let _ = reply.send(out.filter(|v| !v.is_empty()));
+        }
+    }
 }

socktop_agent/src/state.rs

@@ -17,6 +17,10 @@ pub type SharedNetworks = Arc<Mutex<Networks>>;
 pub struct ProcCpuTracker {
     pub last_total: u64,
     pub last_per_pid: HashMap<u32, u64>,
+    /// PID → process name cache. Mirrors the non-Linux `ProcessCache.names`.
+    /// On a Pi with ~150-300 mostly-stable processes this avoids re-allocating
+    /// the same `String`s on every processes poll (~once per 1.5s).
+    pub names: HashMap<u32, String>,
 }
 
 #[cfg(not(target_os = "linux"))]
@@ -70,6 +74,55 @@ pub struct AppState {
     pub cache_journal_entries: Arc<Mutex<HashMap<u32, CacheEntry<crate::types::JournalResponse>>>>,
 }
 
+/// TTL-gated value behind a std Mutex, for `static` caches on hot paths.
+/// Replaces the hand-rolled TempCache/GpuCache/refresh-timestamp statics
+/// that each reimplemented the same at/value pair.
+pub struct TtlCell<T> {
+    inner: std::sync::Mutex<CacheEntry<T>>,
+}
+
+impl<T: Clone> Default for TtlCell<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T: Clone> TtlCell<T> {
+    pub const fn new() -> Self {
+        Self {
+            inner: std::sync::Mutex::new(CacheEntry::new()),
+        }
+    }
+    /// The stored value, only while fresh. Poisoned lock reads as a miss.
+    pub fn get_fresh(&self, ttl: Duration) -> Option<T> {
+        let g = self.inner.lock().ok()?;
+        if g.is_fresh(ttl) {
+            g.value.clone()
+        } else {
+            None
+        }
+    }
+    pub fn set(&self, v: T) {
+        if let Ok(mut g) = self.inner.lock() {
+            g.set(v);
+        }
+    }
+    /// True exactly once per TTL window: restamps and tells the caller to do
+    /// the refresh. Atomic check-and-stamp so concurrent callers don't both
+    /// refresh.
+    pub fn claim_stale(&self, ttl: Duration) -> bool {
+        let Ok(mut g) = self.inner.lock() else {
+            return false;
+        };
+        if g.at.is_none_or(|t| t.elapsed() >= ttl) {
+            g.at = Some(Instant::now());
+            true
+        } else {
+            false
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
 pub struct CacheEntry<T> {
     pub at: Option<Instant>,
@@ -83,7 +136,7 @@ impl<T> Default for CacheEntry<T> {
 }
 
 impl<T> CacheEntry<T> {
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             at: None,
             value: None,

socktop_agent/src/tls.rs

@@ -24,6 +24,17 @@ pub fn cert_paths() -> (PathBuf, PathBuf) {
 pub fn ensure_self_signed_cert() -> anyhow::Result<(PathBuf, PathBuf)> {
     let (cert_path, key_path) = cert_paths();
     if cert_path.exists() && key_path.exists() {
+        // Keys generated by agents older than 1.60 were written with the
+        // default umask (typically 0644): tighten them on startup.
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            if let Ok(meta) = fs::metadata(&key_path)
+                && meta.permissions().mode() & 0o077 != 0
+            {
+                let _ = fs::set_permissions(&key_path, fs::Permissions::from_mode(0o600));
+            }
+        }
         return Ok((cert_path, key_path));
     }
     fs::create_dir_all(cert_path.parent().unwrap())?;
@@ -79,7 +90,16 @@ pub fn ensure_self_signed_cert() -> anyhow::Result<(PathBuf, PathBuf)> {
 
     let mut f = fs::File::create(&cert_path)?;
     f.write_all(cert_pem.as_bytes())?;
-    let mut k = fs::File::create(&key_path)?;
+    // The private key must not be world-readable (File::create honors the
+    // umask, which typically yields 0644).
+    let mut key_opts = fs::OpenOptions::new();
+    key_opts.write(true).create(true).truncate(true);
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::OpenOptionsExt;
+        key_opts.mode(0o600);
+    }
+    let mut k = key_opts.open(&key_path)?;
     k.write_all(key_pem.as_bytes())?;
 
     println!(

socktop_agent/src/types.rs

@@ -30,6 +30,11 @@ pub struct ProcessInfo {
 
 #[derive(Debug, Clone, Serialize)]
 pub struct Metrics {
+    /// Epoch ms when this snapshot was actually collected. The agent serves
+    /// TTL-cached snapshots, so the client needs the AGENT's sample time to
+    /// compute rates — measuring against client receive time turned cache
+    /// hits into a 0-then-2x sawtooth in the network graphs.
+    pub sampled_at_ms: u64,
     pub cpu_total: f32,
     pub cpu_per_core: Vec<f32>,
     pub mem_total: u64,
@@ -93,7 +98,8 @@ pub struct ProcessMetricsResponse {
 
 #[derive(Debug, Clone, Serialize)]
 pub struct JournalEntry {
-    pub timestamp: String, // ISO 8601 formatted timestamp
+    pub timestamp: String, // RFC 3339 UTC, for display
+    pub timestamp_us: u64, // epoch microseconds, for sorting/formatting
     pub priority: LogLevel,
     pub message: String,
     pub unit: Option<String>, // systemd unit name
@@ -120,5 +126,9 @@ pub struct JournalResponse {
     pub entries: Vec<JournalEntry>,
     pub total_count: u32,
     pub truncated: bool,
+    /// journalctl's own explanation when the result is empty because of
+    /// journal ACCESS (not absence of logs) — e.g. a user-run agent asking
+    /// about a system service. None when entries exist or nothing to say.
+    pub notice: Option<String>,
     pub cached_at: u64, // Unix timestamp when this data was cached
 }

socktop_agent/src/ws.rs

@@ -16,9 +16,7 @@ use crate::metrics::{collect_disks, collect_fast_metrics, collect_processes_all}
 use crate::proto::pb;
 use crate::state::AppState;
 
-// Compression threshold based on typical payload size
-// Temporarily increased for testing - revert to 768 for production
-//const COMPRESSION_THRESHOLD: usize = 50_000;
+// Payloads at or below this many bytes are sent as-is; larger ones are gzipped.
 const COMPRESSION_THRESHOLD: usize = 768;
 
 // Reusable buffer for compression to avoid allocations
@@ -52,6 +50,66 @@ pub async fn ws_handler(
     ws.on_upgrade(move |socket| handle_socket(socket, state))
 }
 
+/// Per-PID cache limits: entries older than MAX_AGE are swept on every
+/// insert and the map is capped at MAX_ENTRIES (oldest evicted first), so a
+/// client walking PIDs cannot grow agent memory without bound.
+const PER_PID_CACHE_MAX_AGE: std::time::Duration = std::time::Duration::from_secs(60);
+const PER_PID_CACHE_MAX_ENTRIES: usize = 64;
+
+/// Serve a per-PID request from a TTL cache, collecting on miss. One home
+/// for the logic that get_process_metrics and get_journal_entries used to
+/// duplicate ~50 lines apiece.
+async fn respond_per_pid_cached<T, Fut>(
+    socket: &mut WebSocket,
+    cache: &Mutex<HashMap<u32, crate::state::CacheEntry<T>>>,
+    pid: u32,
+    ttl: std::time::Duration,
+    request_name: &str,
+    collect: impl FnOnce() -> Fut,
+) where
+    T: serde::Serialize + Clone,
+    Fut: std::future::Future<Output = Result<T, String>>,
+{
+    {
+        let cache = cache.lock().await;
+        if let Some(entry) = cache.get(&pid)
+            && entry.is_fresh(ttl)
+            && let Some(v) = entry.get()
+        {
+            let _ = send_json(socket, v).await;
+            return;
+        }
+    }
+    match collect().await {
+        Ok(resp) => {
+            {
+                let mut cache = cache.lock().await;
+                cache.retain(|_, e| e.at.is_some_and(|t| t.elapsed() < PER_PID_CACHE_MAX_AGE));
+                while cache.len() >= PER_PID_CACHE_MAX_ENTRIES {
+                    let oldest = cache.iter().min_by_key(|(_, e)| e.at).map(|(k, _)| *k);
+                    match oldest {
+                        Some(k) => cache.remove(&k),
+                        None => break,
+                    };
+                }
+                cache
+                    .entry(pid)
+                    .or_insert_with(crate::state::CacheEntry::new)
+                    .set(resp.clone());
+            }
+            let _ = send_json(socket, &resp).await;
+        }
+        Err(err) => {
+            let error_response = serde_json::json!({
+                "error": err,
+                "request": request_name,
+                "pid": pid
+            });
+            let _ = send_json(socket, &error_response).await;
+        }
+    }
+}
+
 async fn handle_socket(mut socket: WebSocket, state: AppState) {
     state
         .client_count
@@ -69,12 +127,12 @@ async fn handle_socket(mut socket: WebSocket, state: AppState) {
             Message::Text(ref text) if text == "get_processes" => {
                 let payload = collect_processes_all(&state).await;
 
-                // Map to protobuf message
-                // Get cached buffers
+                // Get cached buffers. The Vec capacity is preserved across
+                // calls (with_capacity(512) seeds it, then we swap-back after
+                // encode so the allocation outlives any single request).
                 let cache = COMPRESSION_CACHE.get_or_init(|| Mutex::new(CompressionCache::new()));
                 let mut cache = cache.lock().await;
 
-                // Reuse process vector to build the list
                 cache.processes_vec.clear();
                 cache
                     .processes_vec
@@ -85,29 +143,38 @@ async fn handle_socket(mut socket: WebSocket, state: AppState) {
                         mem_bytes: p.mem_bytes,
                     }));
 
-                let pb = pb::Processes {
+                // Move the populated Vec into the proto, encode, then move it
+                // BACK into the cache so the next call reuses the same heap
+                // allocation. The previous code did `mem::take(...)` here but
+                // then dropped `pb` (and the Vec along with it), leaving the
+                // cache holding an empty zero-capacity Vec — defeating the
+                // whole point of `with_capacity(512)`.
+                let mut pb = pb::Processes {
                     process_count: payload.process_count as u64,
                     rows: std::mem::take(&mut cache.processes_vec),
                 };
 
                 let mut buf = Vec::with_capacity(8 * 1024);
-                if prost::Message::encode(&pb, &mut buf).is_err() {
+                let encode_result = prost::Message::encode(&pb, &mut buf);
+                // Restore the (now-encoded-from) Vec to the cache before pb is
+                // dropped. We `take` it out of pb to leave that field empty,
+                // and the next request will `.clear()` before refilling.
+                cache.processes_vec = std::mem::take(&mut pb.rows);
+
+                if encode_result.is_err() {
                     let _ = socket.send(Message::Close(None)).await;
+                } else if buf.len() <= COMPRESSION_THRESHOLD {
+                    let _ = socket.send(Message::Binary(buf)).await;
                 } else {
-                    // compress if large
-                    if buf.len() <= COMPRESSION_THRESHOLD {
-                        let _ = socket.send(Message::Binary(buf)).await;
-                    } else {
-                        // Create a new encoder for each message to ensure proper gzip headers
-                        let mut encoder =
-                            GzEncoder::new(Vec::with_capacity(buf.len()), Compression::fast());
-                        match encoder.write_all(&buf).and_then(|_| encoder.finish()) {
-                            Ok(compressed) => {
-                                let _ = socket.send(Message::Binary(compressed)).await;
-                            }
-                            Err(_) => {
-                                let _ = socket.send(Message::Binary(buf)).await;
-                            }
+                    // Create a new encoder for each message to ensure proper gzip headers
+                    let mut encoder =
+                        GzEncoder::new(Vec::with_capacity(buf.len()), Compression::fast());
+                    match encoder.write_all(&buf).and_then(|_| encoder.finish()) {
+                        Ok(compressed) => {
+                            let _ = socket.send(Message::Binary(compressed)).await;
+                        }
+                        Err(_) => {
+                            let _ = socket.send(Message::Binary(buf)).await;
                         }
                     }
                 }
@@ -117,84 +184,30 @@ async fn handle_socket(mut socket: WebSocket, state: AppState) {
                 if let Some(pid_str) = text.strip_prefix("get_process_metrics:")
                     && let Ok(pid) = pid_str.parse::<u32>()
                 {
-                    let ttl = std::time::Duration::from_millis(250); // 250ms TTL
-
-                    // Check cache first
-                    {
-                        let cache = state.cache_process_metrics.lock().await;
-                        if let Some(entry) = cache.get(&pid)
-                            && entry.is_fresh(ttl)
-                            && let Some(cached_response) = entry.get()
-                        {
-                            let _ = send_json(&mut socket, cached_response).await;
-                            continue;
-                        }
-                    }
-
-                    // Collect fresh data
-                    match crate::metrics::collect_process_metrics(pid, &state).await {
-                        Ok(response) => {
-                            // Cache the response
-                            {
-                                let mut cache = state.cache_process_metrics.lock().await;
-                                cache
-                                    .entry(pid)
-                                    .or_insert_with(crate::state::CacheEntry::new)
-                                    .set(response.clone());
-                            }
-                            let _ = send_json(&mut socket, &response).await;
-                        }
-                        Err(err) => {
-                            let error_response = serde_json::json!({
-                                "error": err,
-                                "request": "get_process_metrics",
-                                "pid": pid
-                            });
-                            let _ = send_json(&mut socket, &error_response).await;
-                        }
-                    }
+                    respond_per_pid_cached(
+                        &mut socket,
+                        &state.cache_process_metrics,
+                        pid,
+                        std::time::Duration::from_millis(250),
+                        "get_process_metrics",
+                        || crate::metrics::collect_process_metrics(pid, &state),
+                    )
+                    .await;
                 }
             }
             Message::Text(ref text) if text.starts_with("get_journal_entries:") => {
                 if let Some(pid_str) = text.strip_prefix("get_journal_entries:")
                     && let Ok(pid) = pid_str.parse::<u32>()
                 {
-                    let ttl = std::time::Duration::from_secs(1); // 1s TTL
-
-                    // Check cache first
-                    {
-                        let cache = state.cache_journal_entries.lock().await;
-                        if let Some(entry) = cache.get(&pid)
-                            && entry.is_fresh(ttl)
-                            && let Some(cached_response) = entry.get()
-                        {
-                            let _ = send_json(&mut socket, cached_response).await;
-                            continue;
-                        }
-                    }
-
-                    // Collect fresh data
-                    match crate::metrics::collect_journal_entries(pid) {
-                        Ok(response) => {
-                            // Cache the response
-                            {
-                                let mut cache = state.cache_journal_entries.lock().await;
-                                cache
-                                    .entry(pid)
-                                    .or_insert_with(crate::state::CacheEntry::new)
-                                    .set(response.clone());
-                            }
-                            let _ = send_json(&mut socket, &response).await;
-                        }
-                        Err(err) => {
-                            let error_response = serde_json::json!({
-                                "error": err,
-                                "request": "get_journal_entries",
-                                "pid": pid
-                            });
-                            let _ = send_json(&mut socket, &error_response).await;
-                        }
-                    }
+                    respond_per_pid_cached(
+                        &mut socket,
+                        &state.cache_journal_entries,
+                        pid,
+                        std::time::Duration::from_secs(1),
+                        "get_journal_entries",
+                        || crate::metrics::collect_journal_entries(pid),
+                    )
+                    .await;
                 }
             }
             Message::Close(_) => break,

socktop_agent/tests/cache_tests.rs

@@ -42,6 +42,7 @@ async fn test_process_cache_ttl() {
     };
 
     let journal_response = JournalResponse {
+        notice: None,
         entries: vec![],
         total_count: 0,
         truncated: false,

socktop_agent/tests/process_details.rs

@@ -33,7 +33,7 @@ async fn test_collect_journal_entries_self() {
     // Test collecting journal entries for our own process
     let pid = process::id();
 
-    match collect_journal_entries(pid) {
+    match collect_journal_entries(pid).await {
         Ok(response) => {
             assert!(response.cached_at > 0);
             println!(
@@ -74,7 +74,7 @@ async fn test_collect_journal_entries_invalid_pid() {
     // Test with an invalid PID - journalctl might still return empty results
     let invalid_pid = 999999;
 
-    match collect_journal_entries(invalid_pid) {
+    match collect_journal_entries(invalid_pid).await {
         Ok(response) => {
             println!(
                 "✓ Journal query completed for invalid PID {} (empty result expected): {} entries",
@@ -87,3 +87,19 @@ async fn test_collect_journal_entries_invalid_pid() {
         }
     }
 }
+
+/// The Command & Details pane went blank when the minimal-refresh
+/// optimization dropped cmd from the detail endpoint's refresh kind.
+#[tokio::test]
+async fn test_process_metrics_include_command() {
+    let state = AppState::new();
+    let pid = std::process::id();
+    let resp = collect_process_metrics(pid, &state)
+        .await
+        .expect("collect self");
+    assert!(
+        !resp.process.command.is_empty(),
+        "command should not be empty for self (cmdline is always readable)"
+    );
+    println!("command = {}", resp.process.command);
+}

socktop_connector/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "socktop_connector"
-version = "1.50.0"
+version = "1.60.0"
 edition = "2024"
 license = "MIT"
 description = "WebSocket connector library for socktop agent communication"

socktop_connector/build.rs

@@ -1,8 +1,12 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    // Set the protoc binary path to use the vendored version for CI compatibility
-    // SAFETY: We're only setting PROTOC in a build script environment, which is safe
-    unsafe {
-        std::env::set_var("PROTOC", protoc_bin_vendored::protoc_bin_path()?);
+    // Vendored protoc for reproducible builds where available. It ships no
+    // riscv64 binary, so on such hosts leave $PROTOC / PATH lookup to
+    // prost-build (apt: protobuf-compiler).
+    // SAFETY: We're only setting PROTOC in a build script environment.
+    if let Ok(protoc) = protoc_bin_vendored::protoc_bin_path() {
+        unsafe {
+            std::env::set_var("PROTOC", protoc);
+        }
     }
 
     prost_build::compile_protos(&["processes.proto"], &["."])?;

socktop_connector/src/networking/connection.rs

@@ -6,7 +6,7 @@ use crate::error::{ConnectorError, Result};
 use std::io::BufReader;
 use std::sync::Arc;
 use tokio_tungstenite::tungstenite::client::IntoClientRequest;
-use tokio_tungstenite::{MaybeTlsStream, WebSocketStream, connect_async};
+use tokio_tungstenite::{MaybeTlsStream, WebSocketStream};
 use url::Url;
 
 #[cfg(feature = "tls")]
@@ -15,7 +15,7 @@ use {
     rustls::{
         DigitallySignedStruct, RootCertStore, SignatureScheme,
         client::danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier},
-        crypto::ring,
+        crypto::{WebPkiSupportedAlgorithms, ring},
         pki_types::{CertificateDer, ServerName, UnixTime},
     },
     rustls_pemfile::Item,
@@ -64,7 +64,8 @@ async fn connect_without_ca_and_config(url: &str, config: &ConnectorConfig) -> R
         );
     }
 
-    let (ws, _) = connect_async(req).await?;
+    // `true` disables Nagle: small request/response frames, latency matters.
+    let (ws, _) = tokio_tungstenite::connect_async_with_config(req, None, true).await?;
     Ok(ws)
 }
 
@@ -85,7 +86,12 @@ async fn connect_with_ca_and_config(
             der_certs.push(der);
         }
     }
-    root.add_parsable_certificates(der_certs);
+    if der_certs.is_empty() {
+        return Err(ConnectorError::protocol_error(format!(
+            "no certificates found in --tls-ca file: {ca_path}"
+        )));
+    }
+    root.add_parsable_certificates(der_certs.iter().cloned());
 
     let mut cfg = ClientConfig::builder()
         .with_root_certificates(root)
@@ -114,57 +120,89 @@ async fn connect_with_ca_and_config(
     }
 
     if !config.verify_hostname {
-        #[derive(Debug)]
-        struct NoVerify;
-        impl ServerCertVerifier for NoVerify {
-            fn verify_server_cert(
-                &self,
-                _end_entity: &CertificateDer<'_>,
-                _intermediates: &[CertificateDer<'_>],
-                _server_name: &ServerName,
-                _ocsp_response: &[u8],
-                _now: UnixTime,
-            ) -> std::result::Result<ServerCertVerified, rustls::Error> {
-                Ok(ServerCertVerified::assertion())
-            }
-            fn verify_tls12_signature(
-                &self,
-                _message: &[u8],
-                _cert: &CertificateDer<'_>,
-                _dss: &DigitallySignedStruct,
-            ) -> std::result::Result<HandshakeSignatureValid, rustls::Error> {
-                Ok(HandshakeSignatureValid::assertion())
-            }
-            fn verify_tls13_signature(
-                &self,
-                _message: &[u8],
-                _cert: &CertificateDer<'_>,
-                _dss: &DigitallySignedStruct,
-            ) -> std::result::Result<HandshakeSignatureValid, rustls::Error> {
-                Ok(HandshakeSignatureValid::assertion())
-            }
-            fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
-                vec![
-                    SignatureScheme::ECDSA_NISTP256_SHA256,
-                    SignatureScheme::ED25519,
-                    SignatureScheme::RSA_PSS_SHA256,
-                ]
-            }
-        }
-        cfg.dangerous().set_certificate_verifier(Arc::new(NoVerify));
-        // Note: hostname verification disabled (default). Set SOCKTOP_VERIFY_NAME=1 to enable strict SAN checking.
+        // Default mode: certificate PINNING without hostname verification.
+        // The server must present a certificate byte-identical to one in the
+        // --tls-ca file. This intentionally ignores expiry and chain building
+        // (the operator pinned this exact cert), but unlike a blanket accept
+        // it makes MITM certs fail the handshake.
+        cfg.dangerous()
+            .set_certificate_verifier(Arc::new(PinnedCertVerifier::new(der_certs)));
     }
     let cfg = Arc::new(cfg);
+    // Third argument is tungstenite's `disable_nagle`: always true — socktop
+    // exchanges small request/response frames where Nagle only adds latency.
     let (ws, _) = tokio_tungstenite::connect_async_tls_with_config(
         req,
         None,
-        config.verify_hostname,
+        true,
         Some(Connector::Rustls(cfg)),
     )
     .await?;
     Ok(ws)
 }
 
+/// Accepts exactly the certificates the user pinned via `--tls-ca`, nothing else.
+///
+/// Used when hostname verification is off (the default for self-signed
+/// home-lab certs). Signature validation still runs with the ring provider's
+/// full algorithm set; only the certificate identity check is replaced —
+/// by an exact DER comparison against the pinned certificate(s).
+#[cfg(feature = "tls")]
+#[derive(Debug)]
+struct PinnedCertVerifier {
+    pinned: Vec<CertificateDer<'static>>,
+    algorithms: WebPkiSupportedAlgorithms,
+}
+
+#[cfg(feature = "tls")]
+impl PinnedCertVerifier {
+    fn new(pinned: Vec<CertificateDer<'static>>) -> Self {
+        Self {
+            pinned,
+            algorithms: ring::default_provider().signature_verification_algorithms,
+        }
+    }
+}
+
+#[cfg(feature = "tls")]
+impl ServerCertVerifier for PinnedCertVerifier {
+    fn verify_server_cert(
+        &self,
+        end_entity: &CertificateDer<'_>,
+        _intermediates: &[CertificateDer<'_>],
+        _server_name: &ServerName,
+        _ocsp_response: &[u8],
+        _now: UnixTime,
+    ) -> std::result::Result<ServerCertVerified, rustls::Error> {
+        if self.pinned.iter().any(|p| p == end_entity) {
+            Ok(ServerCertVerified::assertion())
+        } else {
+            Err(rustls::Error::InvalidCertificate(
+                rustls::CertificateError::ApplicationVerificationFailure,
+            ))
+        }
+    }
+    fn verify_tls12_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> std::result::Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls12_signature(message, cert, dss, &self.algorithms)
+    }
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> std::result::Result<HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls13_signature(message, cert, dss, &self.algorithms)
+    }
+    fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
+        self.algorithms.supported_schemes()
+    }
+}
+
 #[cfg(not(feature = "tls"))]
 async fn connect_with_ca_and_config(
     _url: &str,
@@ -181,3 +219,73 @@ async fn connect_with_ca_and_config(
 fn ensure_crypto_provider() {
     let _ = ring::default_provider().install_default();
 }
+
+#[cfg(all(test, feature = "tls"))]
+mod tests {
+    use super::*;
+
+    fn verifier(pinned: &[&[u8]]) -> PinnedCertVerifier {
+        let _ = ring::default_provider().install_default();
+        PinnedCertVerifier::new(
+            pinned
+                .iter()
+                .map(|b| CertificateDer::from(b.to_vec()))
+                .collect(),
+        )
+    }
+
+    fn verify(v: &PinnedCertVerifier, presented: &[u8]) -> bool {
+        v.verify_server_cert(
+            &CertificateDer::from(presented.to_vec()),
+            &[],
+            &ServerName::try_from("agent.test").unwrap(),
+            &[],
+            UnixTime::now(),
+        )
+        .is_ok()
+    }
+
+    /// The regression this verifier exists to prevent: the old NoVerify
+    /// accepted ANY certificate when hostname verification was off, so the
+    /// documented pinning was a no-op. The pinned cert must be accepted and
+    /// every other cert rejected.
+    #[test]
+    fn only_the_pinned_certificate_is_accepted() {
+        let v = verifier(&[b"pinned-cert-der"]);
+        assert!(verify(&v, b"pinned-cert-der"));
+        assert!(!verify(&v, b"some-mitm-cert"), "unpinned cert accepted");
+        assert!(!verify(&v, b""), "empty cert accepted");
+    }
+
+    /// A --tls-ca file may hold several certs (e.g. during rotation); any of
+    /// them must satisfy the pin.
+    #[test]
+    fn any_cert_in_a_multi_cert_pem_satisfies_the_pin() {
+        let v = verifier(&[b"old-cert", b"new-cert"]);
+        assert!(verify(&v, b"old-cert"));
+        assert!(verify(&v, b"new-cert"));
+        assert!(!verify(&v, b"third-party-cert"));
+    }
+
+    /// Fail closed: an empty pin set must reject everything rather than
+    /// falling back to accept-all.
+    #[test]
+    fn an_empty_pin_set_rejects_all_certificates() {
+        let v = verifier(&[]);
+        assert!(!verify(&v, b"anything"));
+    }
+
+    /// Signature schemes come from the real provider, not a hardcoded list —
+    /// an agent using e.g. RSA-PKCS1 must still be able to handshake.
+    #[test]
+    fn signature_schemes_come_from_the_provider() {
+        let v = verifier(&[b"x"]);
+        let schemes = v.supported_verify_schemes();
+        assert!(
+            schemes.len() > 3,
+            "suspiciously short scheme list: {schemes:?}"
+        );
+        assert!(schemes.contains(&SignatureScheme::RSA_PKCS1_SHA256));
+        assert!(schemes.contains(&SignatureScheme::ECDSA_NISTP256_SHA256));
+    }
+}

socktop_connector/src/types.rs

@@ -54,6 +54,10 @@ pub struct GpuInfo {
 
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct Metrics {
+    /// Epoch ms when the agent actually collected this snapshot (agents may
+    /// serve TTL-cached data). Absent on agents older than 1.60.
+    #[serde(default)]
+    pub sampled_at_ms: Option<u64>,
     pub cpu_total: f32,
     pub cpu_per_core: Vec<f32>,
     pub mem_total: u64,
@@ -147,6 +151,10 @@ pub struct JournalResponse {
     pub entries: Vec<JournalEntry>,
     pub total_count: u32,
     pub truncated: bool,
+    /// Agent-side explanation for an empty result (journal access limits).
+    /// Absent on agents older than 1.60.
+    #[serde(default)]
+    pub notice: Option<String>,
     pub cached_at: u64, // Unix timestamp when this data was cached
 }
 

socktop_connector/src/wasm/requests.rs

@@ -46,6 +46,7 @@ pub async fn send_request_and_wait(
                 // For now, return a placeholder metrics response indicating binary data received
                 // TODO: Implement proper protobuf decoding for binary data
                 let placeholder_metrics = Metrics {
+                    sampled_at_ms: None,
                     cpu_total: 0.0,
                     cpu_per_core: vec![0.0],
                     mem_total: 0,

socktop_wasm_test/Cargo.lock

@@ -37,9 +37,9 @@ checksum = "46c5e41b57b8bba42a04676d81cb89e9ee8e859a1a66f80a5a72e1cb76b34d43"
 
 [[package]]
 name = "bytes"
-version = "1.10.1"
+version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d71b6127be86fdcfddb610f7182ac57211d4b18a3e9c82eb2d17662f2227ad6a"
+checksum = "1e748733b7cbc798e1434b6ac524f0c1ff2ab456fe201501e6497c8417a4fc33"
 
 [[package]]
 name = "cfg-if"
@@ -475,9 +475,7 @@ dependencies = [
 
 [[package]]
 name = "socktop_connector"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a63dadaa5105df11b0684759a829012257d48e72a469cc554c0cf4394605f5a"
+version = "1.51.0"
 dependencies = [
  "flate2",
  "js-sys",

socktop_wasm_test/Cargo.toml

@@ -10,8 +10,8 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-# Use WASM features for WebSocket connectivity (published version)
-socktop_connector = { version = "0.1.5", default-features = false, features = ["wasm"] }
+# Use WASM features for WebSocket connectivity (in-repo connector via path)
+socktop_connector = { path = "../socktop_connector", default-features = false, features = ["wasm"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 wasm-bindgen = "0.2"

zellij_socktop_plugin/Cargo.toml

@@ -3,6 +3,9 @@ name = "zellij_socktop_plugin"
 version = "0.1.0"
 edition = "2021"
 
+# Standalone package, not part of the parent workspace (same as socktop_wasm_test)
+[workspace]
+
 [lib]
 crate-type = ["cdylib"]
 
@@ -10,7 +13,7 @@ crate-type = ["cdylib"]
 zellij-tile = "0.40.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-socktop_connector = { version = "0.1.5", default-features = false, features = ["wasm"] }
+socktop_connector = { path = "../socktop_connector", default-features = false, features = ["wasm"] }
 futures = "0.3"
 
 [dependencies.chrono]