Filter Tune

Run the filter calibration pipeline in order:

1. Check that a baseline exists:
   ls scripts/filter-baseline.json 2>/dev/null || echo MISSING
   If MISSING, run npm run test:filter:baseline first and stop —
   do not proceed to calibrate without a baseline.

2. Run the current report: npm run test:filter

3. If the user confirmed calibration is wanted:
   npm run test:filter:calibrate

4. Run the comparison: npm run test:filter:compare

5. Summarize: how many queries improved / regressed / unchanged.
   Flag any category where pass rate dropped more than 5 percentage points.

Do not modify any threshold files manually — only the calibrate script
should write thresholds.