This PR restores critical fixes for repository metrics and CI cost optimizations that were identified as missing from the filesystem despite being marked as completed in previous tasks.
### Changes:
- **Metrics Accuracy**: Re-implemented 7-day fixed window and search-based sampling in `throughput.ts`, `latency.ts`, and `user_touches.ts` to resolve reporting anomalies during batch operations.
- **Spend Tracking**: Implemented pagination in `actions_spend.ts` to ensure all workflow runs within the 7-day window are captured, avoiding undercounting.
- **CI Cost Optimization**: Replaced all instances of `macos-latest-large` with standard `macos-latest` runners in `ci.yml`, `chained_e2e.yml`, and `deflake.yml`.
- **Matrix Reduction**: Reduced the Mac test matrix in `ci.yml` to Node 20.x only, significantly reducing redundant compute spend.
- **Task Ledger**: Updated `lessons-learned.md` to document the logic divergence and its resolution (BT-63).
These changes ensure the repository metrics are reliable and that CI costs remain under control.
gemini-cli[bot]