7095e23eb2
Persist fork token usage under session_model_usage task=background_review, emit a per-fork completion log line, and expose enabled/max_iterations/ prompt_file so operators can see and bound the automatic review cost. Address review feedback: load auxiliary.background_review once per spawn, classify completion logs by summarize action prefixes, treat explicit api_call_count=None as the documented default of 1, and WARNING on the fail-open enabled-gate path.