cleanup: remove dead code and duplicate docs

- Remove session-ses_2f27.md (161KB raw session log)
- Remove 49 ROOT_* duplicate files across REFERENCE/
- Remove 14 duplicate files between REFERENCE/ root and history/
- Remove asr_legacy.rs (dead code, replaced by asr.rs)
- Remove src/core/worker/ (duplicate JobWorker)
- Remove src/core/layers/ (empty directory)
- Remove 4 .bak files in src/
- Remove 7 dead private methods in worker/processor.rs
- Remove backup directory from git tracking

scripts/backfill_demographics.py

@@ -4,11 +4,9 @@ Backfill missing Age & Gender for persons.
 """
 
 import os
-import sys
 import cv2
 import psycopg2
 import insightface
-import numpy as np
 
 DB_CONFIG = {"host": "localhost", "user": "accusys", "dbname": "momentry"}
 BASE_VIDEO_DIR = "output"
@@ -94,7 +92,7 @@ def main():
             else:
                 print(f"  -> Detection incomplete (Age:{age}, Gender:{gender})")
         else:
-            print(f"  -> No face found in frame.")
+            print("  -> No face found in frame.")
 
     print("=== Done ===")
     conn.close()