protobuff Process list

BREAKING: Process list over WS is now Protocol Buffers; client required.
Agent: returns all processes (no server-side top-k); large payloads gzip-compressed.
Client: decodes protobuf (gz/raw), moves sorting/pagination to TUI.
Build: add prost/prost-build with vendored protoc; enable thin LTO, panic=abort, strip symbols.
Cleanup: cfg-gate Linux-only code; fix Clippy across platforms; tests updated (ws probe TLS CA).

socktop_agent/Cargo.toml

@@ -27,6 +27,14 @@ rustls-pemfile = "2.1"
 openssl = { version = "0.10", features = ["vendored"] }  # for cross‑platform self‑signed generation
 anyhow = "1"
 hostname = "0.3"
+bytes = { workspace = true }
+prost = { workspace = true }
+
+[build-dependencies]
+prost-build = "0.13"
+prost-types = { workspace = true }
+tonic-build = { version = "0.12", default-features = false, optional = true }
+protoc-bin-vendored = "3"
 [dev-dependencies]
 assert_cmd = "2.0"
 tempfile = "3.10"