fix: face group name read consistency, sync_file_status fix, cleanup ghost records, identity_agent replaced with face_dedup

- get_face_groups_handler: COALESCE(tp.name, tn.label) for name consistency
- sync_file_status: compare JSON vs pre_chunks (not chunk table)
- face consistency: compare frames.len() not total_faces
- cleanup 2 ghost records with NULL file_name/file_path
- replace identity_agent with face_dedup in pipeline stages
- remove identity_agent_api.rs and all references
- update required_processors to match actual processors
- update AGENTS.md with team responsibilities
- add Studio pipeline changes documentation

scripts/yolo_processor.py

@@ -483,6 +483,7 @@ if __name__ == "__main__":
         action="store_true",
         help="Force restart from beginning (ignore existing data)",
     )
+    parser.add_argument("--frames", type=str, default=None, help=argparse.SUPPRESS)
 
     args = parser.parse_args()