Add TranscriptSegment capnp schema and append-only log for tracking
which transcript segments have been mined by which agents. Replaces
the old approach of creating stub nodes (_observed-transcripts,
_mined-transcripts, _facts-) in the main graph store.
- New schema: TranscriptSegment and TranscriptProgressLog
- Store methods: append_transcript_progress, replay, is_segment_mined,
mark_segment_mined
- Migration command: admin migrate-transcript-progress (migrated 1771
markers, soft-deleted old stub nodes)
- Progress log replayed on all Store::load paths
Also: revert extractor.agent to graph-only (no CONVERSATIONS),
update memory-instructions-core with refine-over-create principle.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
835b392b7a