feat: Phase 2.6 edges migration to Qdrant (TKG-only architecture)

Phase 2.6.1: co_occurrence_edges migration
- build_co_occurrence_edges_from_qdrant()
- Qdrant embeddings → frame grouping → YOLO objects
- Result: 6679 edges (vs 6701 PostgreSQL)

Phase 2.6.2: face_face_edges migration
- build_face_face_edges_from_qdrant()
- Qdrant embeddings → frame grouping → face pairs
- mutual_gaze detection preserved
- Result: 6 edges (exact match)

Phase 2.6.3: speaker_face_edges migration
- build_speaker_face_edges_from_qdrant()
- Qdrant embeddings → trace_id frame ranges
- SPEAKS_AS edge creation

Architecture:
- All edges use Qdrant payload (no face_detections queries)
- PostgreSQL fallback for empty Qdrant
- Estimated 3.6x performance improvement

Testing:
- Playground (3003): ✓ All Phase 2.6 logs verified
- Edge counts: ✓ Close match with PostgreSQL
- Fallback: ✓ Working

Docs:
- docs_v1.0/DESIGN/TKG_PHASE2_6_EDGES_MIGRATION.md
- docs_v1.0/M4_workspace/2026-06-21_phase2_6_test.md

v1.1/scripts/backfill_demographics_v1.11.py

@@ -0,0 +1,102 @@
+#!/opt/homebrew/bin/python3.11
+"""
+Backfill missing Age & Gender for persons.
+"""
+
+import os
+import cv2
+import psycopg2
+import insightface
+
+DB_CONFIG = {"host": "localhost", "user": "accusys", "dbname": "momentry"}
+BASE_VIDEO_DIR = "output"
+
+
+def main():
+    print("=== Starting Missing Demographics Backfill ===")
+
+    conn = psycopg2.connect(**DB_CONFIG)
+    cur = conn.cursor()
+
+    # Load Model
+    print("Loading InsightFace model...")
+    try:
+        app = insightface.app.FaceAnalysis(
+            name="buffalo_l", providers=["CPUExecutionProvider"]
+        )
+        app.prepare(ctx_id=0, det_size=(320, 320))
+        print("Model loaded.")
+    except Exception as e:
+        print(f"Error loading model: {e}")
+        return
+
+    # Query persons missing data
+    # Join with appearances to find a valid timestamp
+    cur.execute("""
+        SELECT DISTINCT ON (pi.person_id) pi.person_id, pa.video_uuid, pa.start_time
+        FROM person_identities pi
+        JOIN person_appearances pa ON pi.person_id = pa.person_id
+        WHERE pi.age IS NULL OR pi.gender IS NULL
+        ORDER BY pi.person_id, pa.start_time
+    """)
+    rows = cur.fetchall()
+
+    print(f"Found {len(rows)} entries to process.")
+
+    for i, (person_id, video_uuid, start_time) in enumerate(rows):
+        # Skip if time is null
+        if start_time is None:
+            continue
+
+        print(f"[{i + 1}/{len(rows)}] Processing: {person_id} @ {start_time:.1f}s")
+
+        video_path = f"{BASE_VIDEO_DIR}/{video_uuid}/{video_uuid}.mp4"
+        if not os.path.exists(video_path):
+            print(f"  -> Video not found at {video_path}")
+            continue
+
+        cap = cv2.VideoCapture(video_path)
+        if not cap.isOpened():
+            print("  -> Could not open video.")
+            continue
+
+        # Seek
+        cap.set(cv2.CAP_PROP_POS_MSEC, start_time * 1000)
+        ret, frame = cap.read()
+        cap.release()
+
+        if not ret or frame is None:
+            print("  -> Failed to read frame.")
+            continue
+
+        faces = app.get(frame)
+        if faces:
+            face = faces[0]
+            age = int(face.age) if hasattr(face, "age") else None
+            gender_val = face.gender if hasattr(face, "gender") else None
+            gender = (
+                "female" if gender_val == 0 else ("male" if gender_val == 1 else None)
+            )
+
+            if age is not None and gender is not None:
+                cur.execute(
+                    """
+                    UPDATE person_identities 
+                    SET age = %s, gender = %s 
+                    WHERE person_id = %s
+                """,
+                    (age, gender, person_id),
+                )
+                conn.commit()
+                print(f"  -> Updated: Age {age}, Gender {gender}")
+            else:
+                print(f"  -> Detection incomplete (Age:{age}, Gender:{gender})")
+        else:
+            print("  -> No face found in frame.")
+
+    print("=== Done ===")
+    conn.close()
+
+
+if __name__ == "__main__":
+    main()