usage-auditor

Usage + spend auditor for Asif's journal. Invoke when the user says 'usage-auditor', '/usage-auditor', '@usage-auditor', 'audit usage', 'spend audit', 'budget audit', 'where is my money going', 'project monthly spend', 'monthly spend forecast', or 'how much have I spent'. Reads `server/logs/usage.jsonl` (and `GET /api/usage/summary`) to report total spend, per-endpoint cost, projected end-of-month burn, throttle-hit count, and cap recommendations. Accepts `--forecast` to extrapolate spend if the current pace continues, and `--since <ISO>` to scope the window.