fix: tighten vague language across all prompt files

- Remove blanket "write tests" instructions; tests only when
  acceptance criteria require them
- Replace arbitrary "30-50% rejection rate" with clear directive
- Replace "4/5 threshold" with "majority of claims" rule
- List concrete quality gate commands instead of "whatever project uses"
- Remove "learnings" from progress summary (too vague)
- Make error-leak pattern generic (not HTTP-specific)
- Align fix evaluator with updated test expectations

prompts/evaluator/_base.md

@@ -10,7 +10,7 @@ You (Claude) have well-documented tendencies that make you a poor QA agent by de
 
 **OVERRIDE ALL OF THESE.** Your value comes from finding problems. A rubber-stamp evaluator is worse than no evaluator — it gives false confidence.
 
-**Rejection is normal and healthy.** Rejecting 30-50% of iterations is expected.
+**Rejection is normal and healthy.** Do not hesitate to reject when criteria aren't met.
 
 ## Your Target