Add in-memory trace analysis commands

[V3RON]

Summary

• add in-memory trace sessions so trace stop analyzes captured events and agents can inspect them without reading raw trace files
• add trace status|list|summary|tracks|entries|entry commands with compact, filterable output for user timings and custom DevTools tracks
• keep raw trace recording opt-in and backward-compatible by preserving trace start / trace stop [--file PATH] while routing parsing into a separate src/trace/ module

Backward Compatibility

• Existing trace capture remains explicit: tracing still starts only when trace start is invoked.
• trace stop --file PATH still exports raw traceEvents JSON; it now also creates an in-memory analyzed session and returns a richer summary.
• Existing daemon lifecycle, target/session flow, and newline-delimited IPC remain unchanged.
• The CLI surface only adds new trace subcommands and does not change defaults for other command families.

Risks

• User timing parsing currently relies on a lightweight normalization layer rather than a full DevTools handler port, so uncommon trace event shapes may still be missed.
• Track grouping and console timestamp range reconstruction are derived from recorded trace data; unusual producer behavior could land entries on the default track.
• In-memory session retention is bounded, which keeps token and memory usage under control but means older trace sessions are evicted after the cap is reached.

Manual testing

• Setup: run the daemon, select a Chrome target, and load a page that emits performance.measure, performance.mark, and optional custom DevTools track metadata.
• Start capture: run agent-cdp trace start, exercise the page, then run agent-cdp trace stop --file /tmp/trace.json.
• Verify summary: run agent-cdp trace summary and confirm it reports a new session with entry counts and top tracks.
• Verify navigation: run agent-cdp trace tracks, then agent-cdp trace entries --track Timings, and finally agent-cdp trace entry --id <ENTRY_ID> to confirm drill-down output stays compact and filterable.
• Verify compatibility: open /tmp/trace.json and confirm raw traceEvents were still exported.

Validation

• pnpm format
• pnpm lint
• pnpm typecheck
• pnpm test
• pnpm build

Closes #12