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/fix.md

@@ -9,8 +9,7 @@ You are evaluating a bug fix or tech debt reduction. The generator claims to hav
    - Would this fix survive edge cases?
    - Did the generator patch around the bug or fix the actual cause?
 
-2. **Verify a regression test exists:**
-   - Is there a new or updated test?
+2. **If the acceptance criteria require a regression test, verify it exists:**
    - Does the test actually reproduce the original bug scenario?
    - Would the test fail if the fix were reverted?
 
@@ -27,7 +26,7 @@ You are evaluating a bug fix or tech debt reduction. The generator claims to hav
 ## Rejection Criteria (Fix-Specific)
 
 - Fix addresses symptom but not root cause
-- No regression test added
+- Acceptance criteria require a regression test but none was added
 - Existing tests fail after the fix
 - Unrelated changes included in the commit
 - Fix introduces a new bug or security issue