feat: Phase 2-3 TKG-only architecture

Phase 2.1: build_face_trace_nodes_from_qdrant()
- Read trace_id, frame, bbox directly from Qdrant payload
- No dependency on face_detections table

Phase 2.3: Rule2 queries TKG nodes
- identity resolution from tkg_nodes.properties.identity_id
- TKG-only architecture (Phase 2.3)

Phase 3: Identity Agent updates TKG nodes
- match_faces_iterative() updates tkg_nodes.properties
- bind_identity_trace() syncs identity_id to TKG
- unbind_identity() removes identity_id from TKG

Test results:
- 23 face_trace nodes from Qdrant (Phase 2.1)
- 75 relationship chunks (Rule2)
- TKG rebuild: Phase0 → Phase1 → Phase2

docs_v1.0/M4_workspace/2026-06-21_tkg_phase2_progress.md

@@ -0,0 +1,69 @@
+---
+title: TKG Phase 2-3 Progress Report
+version: 1.0
+date: 2026-06-21
+author: OpenCode
+status: In Progress
+---
+
+## Goal
+- Complete TKG-only architecture migration: Phase 0-4 for Rule 2 relationship chunks and Identity Agent Qdrant integration
+
+## Constraints & Preferences
+- Rule 2 chunk_type: `"relationship"` (not `"visual"`)
+- Rule 2 edge types match TKG storage: `SPEAKS_AS`, `MUTUAL_GAZE`, `CO_OCCURS_WITH`, `HAS_APPEARANCE`, `WEARS`
+- Rule 2 each edge = one chunk (not aggregated)
+- Qdrant face embeddings: dim=512, Cosine distance, collection `{schema}_face_embeddings`
+- Phase approach: Phase 0 (populate), Phase 1 (Qdrant), Phase 2 (TKG-only), Phase 3 (Identity), Phase 4 (deprecate)
+
+## Progress
+### Done
+- **Phase 0**: TKG builder populate face_detections from face.json via `store_traced_faces.py`
+- **Phase 1.1**: Create `dev_face_embeddings` Qdrant collection (dim=512)
+- **Phase 1.2**: `FaceEmbeddingDb` module with `init_collection`, `batch_upsert`, `search_similar`, `get_all_embeddings_for_file`
+- **Phase 1.3**: TKG builder stores 1122 embeddings to Qdrant with pose metadata
+- **Phase 1.4**: Identity Agent `match_faces_iterative()` queries Qdrant (fallback to PG)
+- **Phase 2.1**: `build_face_trace_nodes_from_qdrant()` reads Qdrant payload (no face_detections dependency)
+- **Phase 2.3**: Rule2 queries `tkg_nodes.properties.identity_id` (TKG-only)
+- **Phase 3**: Identity Agent (Qdrant + PG) updates `tkg_nodes.properties` when binding
+- **Rule 2**: 75 relationship chunks created + vectorized (tested)
+- **Rule 2 API**: `POST /api/v1/file/:file_uuid/rule2` with auto-vectorize, triggers on TKG rebuild
+- **Identity binding**: `bind_identity_trace()` and `unbind_identity()` update TKG nodes (Phase 2.3)
+- **TKG builder**: `populate_face_detections_from_face_json()` and `populate_face_embeddings_to_qdrant()`
+
+### Pending
+- **Phase 4**: Deprecate face_detections table (await all Phase 2-3 verified in production)
+
+## Key Decisions
+- TKG builder fixed for `pose_angle` format (was expecting `pose` with `bbox` sub-object)
+- Edge types corrected: TKG stores `CO_OCCURS_WITH` (not `co_occurs`), `SPEAKS_AS` (not `speaker_face`)
+- Qdrant point IDs must be numeric or UUID (not string like `"file_uuid-frame"`)
+- Identity Agent dual-source: Qdrant first, PostgreSQL fallback
+- Phase 0 checks `trace_id IS NOT NULL` before calling `store_traced_faces.py`
+- Phase 2.1: Qdrant payload contains `trace_id`, `frame`, `bbox_x/y/w/h`, `pose`, no PG query needed
+- Phase 2.3: TKG nodes store `identity_id` and `identity_name` in properties JSON
+- Phase 3: Identity Agent updates both `face_detections.identity_id` AND `tkg_nodes.properties`
+
+## Test Results
+- 1122 face embeddings in Qdrant (`dev_face_embeddings` collection)
+- 75 relationship chunks from Rule2
+- 23 face_trace_nodes built from Qdrant (Phase 2.1)
+- Rule2 still works after TKG-only migration (Phase 2.3)
+
+## Next Steps
+- Phase 4: Verify all systems work without face_detections dependency
+- Phase 4: Document face_detections deprecation plan
+
+## Commits
+- `2f2ccc94` (Phase 1.4)
+- `3ad6f874` (Rule2 + Phase 0-1)
+- (pending) Phase 2-3 changes
+
+## Relevant Files
+- `src/core/db/face_embedding_db.rs`: **New** — FaceEmbeddingDb, FaceEmbeddingPayload, FaceEmbeddingPoint
+- `src/core/db/mod.rs`: updated — `pub mod face_embedding_db; pub use FaceEmbeddingDb;`
+- `src/core/processor/tkg.rs`: updated — Phase 2.1 `build_face_trace_nodes_from_qdrant()`
+- `src/core/chunk/rule2_ingest.rs`: updated — Phase 2.3 TKG-only identity query
+- `src/api/identity_binding.rs`: updated — Phase 2.3 TKG node update on bind/unbind
+- `src/api/identity_agent_api.rs`: updated — Phase 3 TKG node update on match
+- `docs_v1.0/DESIGN/RULE2_TKG_RELATIONSHIP_V1.0.md`: Rule 2 design spec