docs: add per-crate README.md and link via Cargo.toml readme field

socktop_agent/Cargo.toml

@@ -5,6 +5,7 @@ authors = ["Jason Witty <jasonpwitty+socktop@proton.me>"]
 description = "Remote system monitor over WebSocket, TUI like top"
 edition = "2021"
 license = "MIT"
+readme = "README.md"
 
 [dependencies]
 tokio = { version = "1", features = ["full"] }

socktop_agent/README.md

@@ -0,0 +1,32 @@
+# socktop_agent (server)
+
+Lightweight on‑demand metrics WebSocket server for the socktop TUI.
+
+Highlights:
+- Collects system metrics only when requested (keeps idle CPU <1%)
+- Optional TLS (self‑signed cert auto‑generated & pinned by client)
+- JSON for fast metrics / disks; protobuf (optionally gzipped) for processes
+- Accurate per‑process CPU% on Linux via /proc jiffies delta
+- Optional GPU & temperature metrics (disable via env vars)
+- Simple token auth (?token=...) support
+
+Run (no TLS):
+```
+cargo install socktop_agent
+socktop_agent --port 3000
+```
+Enable TLS:
+```
+SOCKTOP_ENABLE_SSL=1 socktop_agent --port 8443
+# cert/key stored under $XDG_DATA_HOME/socktop_agent/tls
+```
+Environment toggles:
+- SOCKTOP_AGENT_GPU=0      (disable GPU collection)
+- SOCKTOP_AGENT_TEMP=0     (disable temperature)
+- SOCKTOP_TOKEN=secret     (require token param from client)
+- SOCKTOP_AGENT_METRICS_TTL_MS=250 (cache fast metrics window)
+- SOCKTOP_AGENT_PROCESSES_TTL_MS=1000
+- SOCKTOP_AGENT_DISKS_TTL_MS=1000
+
+Systemd unit example & full docs:
+https://github.com/jasonwitty/socktop