fix: lower first-attempt threshold to 20% to match observed baseline

Two eval runs show ~21-27% first-attempt rate. The correction loop
consistently brings it to 93-100%. Set threshold at 20% to catch
regressions without failing on normal variance.

Author: nicknisi

tests/evals/success-criteria.spec.ts

@@ -15,7 +15,7 @@ function makeResult(passed: boolean, attempts: number = 1, correctionAttempts: n
 describe('success-criteria', () => {
   describe('DEFAULT_CRITERIA', () => {
     it('has expected default thresholds', () => {
-      expect(DEFAULT_CRITERIA.firstAttemptPassRate).toBe(0.3);
+      expect(DEFAULT_CRITERIA.firstAttemptPassRate).toBe(0.2);
       expect(DEFAULT_CRITERIA.withCorrectionPassRate).toBe(0.9);
       expect(DEFAULT_CRITERIA.withRetryPassRate).toBe(0.95);
     });
@@ -44,14 +44,12 @@ describe('success-criteria', () => {
     });
 
     it('returns passed=false when first-attempt rate below threshold', () => {
-      // 10 results, only 2 passed on first attempt (20% < 30% threshold)
+      // 10 results, only 1 passed on first attempt (10% < 20% threshold)
       const results: EvalResult[] = [
-        ...Array(2)
-          .fill(null)
-          .map(() => makeResult(true, 1)),
-        ...Array(7)
+        makeResult(true, 1, 0),
+        ...Array(8)
           .fill(null)
-          .map(() => makeResult(true, 2)),
+          .map(() => makeResult(true, 1, 1)),
         makeResult(true, 2),
       ];
 

tests/evals/success-criteria.ts

@@ -17,7 +17,7 @@ export interface SuccessCriteria {
 
 /** Default thresholds for CI enforcement */
 export const DEFAULT_CRITERIA: SuccessCriteria = {
-  firstAttemptPassRate: 0.3,
+  firstAttemptPassRate: 0.2,
   withCorrectionPassRate: 0.9,
   withRetryPassRate: 0.95,
 };