90b20879d2
Migrates the 2 remaining _cb_* sites with proper Result[T] propagation: - _cb_run_conductor_setup: per-file read via _read_conductor_file_result - _cb_load_track: state hydration via _cb_load_track_result New helpers: - _read_conductor_file_result(f) -> Result[int] - _cb_load_track_result(state, track_id) -> Result[None] Audit: INTERNAL_SILENT_SWALLOW for src/app_controller.py: 12 -> 10.