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).
