- Add session recording metadata and mux filter builder in src/recorder/sessionRecording.ts.
- Update SegmentMetadata to include recordingSessionId in src/types.ts and src/recorder/metadata.ts.
- Modify recorder lifecycle to track sessions, register segments, and finalize recordings on stop.
- Create tests for session recording functionality in tests/recorder/sessionRecording.test.ts and tests/recorder/metadata.test.ts.
- Document session recording design and implementation plan in docs/superpowers/specs/2026-05-16-session-full-recording-design.md and docs/superpowers/plans/2026-05-16-session-full-recording.md.