test(harness): isProseAUQVisible — lower numbered threshold to 2 (matches lettered)

The 4KB tail window often contains only options 2-4 of a 4-option
numbered prose AUQ because the model emits the question header + option 1
several KB earlier in the buffer. The threshold of 3 distinct numbered
markers caused the detector to miss real prose AUQs whenever option 1
had scrolled out.

Threshold 2 matches the lettered branch and is still tightly gated by:
- Line-start anchoring (no false positives on inline `1.` references)
- No-cursor gate (defers to native UI when ❯ 1. is currently rendered)
- The 4KB tail window itself (prose-AUQ rendering happens at the end of
  the model's response, so options are clustered in the tail)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/helpers/claude-pty-runner.ts

@@ -519,12 +519,18 @@ export function isProseAUQVisible(visible: string): boolean {
   }
   if (letteredHits.size >= 2) return true;
 
-  // Pattern 2: 3+ distinct numbered options at line starts, AND no
+  // Pattern 2: 2+ distinct numbered options at line starts, AND no
   // `❯<spaces>1.` cursor IN THE RECENT TAIL (not the full buffer — a
   // trust-dialog `❯ 1. Yes` at boot is in scrollback forever and
   // would otherwise suppress this path for the rest of the run).
   // The native-UI deferral only applies when the cursor list is
   // currently rendered, not historically.
+  //
+  // Threshold 2 (matching the lettered branch): the tail is a 4KB window,
+  // and by the time the polling loop sees it, the model may have emitted
+  // option 1 several KB earlier and only 2/3/4 remain in tail. False
+  // positives on prose ("First, x. Second, y.") are extremely rare given
+  // the line-start anchor + the no-cursor gate.
   if (/❯\s*1\./.test(tail)) return false;
   const numberedRe = /(?:^|\n)[ \t❯]*([1-9])\./g;
   const numberedHits = new Set<string>();
@@ -532,7 +538,7 @@ export function isProseAUQVisible(visible: string): boolean {
   while ((nm = numberedRe.exec(tail)) !== null) {
     if (nm[1]) numberedHits.add(nm[1]);
   }
-  return numberedHits.size >= 3;
+  return numberedHits.size >= 2;
 }
 
 /**

test/helpers/claude-pty-runner.unit.test.ts

@@ -254,10 +254,17 @@ A) Only one option mentioned in passing.
     expect(isProseAUQVisible(sample)).toBe(false);
   });
 
-  test('returns false on 2 numbered options (need 3+ for prose numbered)', () => {
+  test('matches 2 numbered options (threshold matches lettered branch — tails miss option 1)', () => {
     const sample = `
 1. First note.
 2. Second note.
+`;
+    expect(isProseAUQVisible(sample)).toBe(true);
+  });
+
+  test('returns false on a single numbered option', () => {
+    const sample = `
+1. Only one option mentioned.
 `;
     expect(isProseAUQVisible(sample)).toBe(false);
   });