test(harness): isProseAUQVisible — gate numbered path on tail, not full buffer

The numbered-options branch of isProseAUQVisible deferred to
isNumberedOptionListVisible whenever a `❯ 1.` cursor was visible in the
full buffer. But the boot trust dialog (`❯ 1. Yes, trust`) lives in
scrollback for the entire run, so this gate suppressed prose-numbered
detection for any session that had the trust prompt at startup —
i.e., every E2E run after the first user-trust acceptance.

Fix: check only the last 4KB tail. Native-UI deferral applies when
the cursor list is CURRENTLY rendered, not historically present in
scrollback.

Adds a regression test that puts the trust dialog in early scrollback
+ 5KB filler + a current prose-AUQ render, asserts true.

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

test/helpers/claude-pty-runner.ts

@@ -519,10 +519,13 @@ export function isProseAUQVisible(visible: string): boolean {
   }
   if (letteredHits.size >= 2) return true;
 
-  // Pattern 2: 3+ distinct numbered options at line starts, AND no `❯<spaces>1.`
-  // cursor anywhere in the FULL visible buffer (which would mean
-  // isNumberedOptionListVisible already covers the case via the native UI).
-  if (/❯\s*1\./.test(visible)) return false;
+  // Pattern 2: 3+ 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.
+  if (/❯\s*1\./.test(tail)) return false;
   const numberedRe = /(?:^|\n)[ \t❯]*([1-9])\./g;
   const numberedHits = new Set<string>();
   let nm: RegExpExecArray | null;

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

@@ -226,7 +226,7 @@ What's the task? A few options:
     expect(isProseAUQVisible(sample)).toBe(true);
   });
 
-  test('returns false when ❯ 1. cursor is present (native UI handled by isNumberedOptionListVisible)', () => {
+  test('returns false when ❯ 1. cursor is present in the recent tail (native UI handled by isNumberedOptionListVisible)', () => {
     const sample = `
 ❯ 1. First option
   2. Second option
@@ -235,6 +235,18 @@ What's the task? A few options:
     expect(isProseAUQVisible(sample)).toBe(false);
   });
 
+  test('does NOT suppress numbered-prose detection when ❯ 1. is only in early scrollback (trust dialog)', () => {
+    // Boot trust dialog rendered ❯ 1. Yes at startup, then a long body of
+    // model output, then prose-rendered numbered options now. The historic
+    // ❯ 1. is in the full buffer but NOT in the recent tail. Should detect
+    // the prose AUQ.
+    const trustHeader = '❯ 1. Yes, trust\n  2. No\n';
+    const filler = 'x'.repeat(5000); // pushes trust dialog out of last 4KB tail
+    const proseAUQ = `\n  1. Review the docs\n  2. Investigate the code\n  3. Defer to next session\n❯  \n`;
+    const sample = trustHeader + filler + proseAUQ;
+    expect(isProseAUQVisible(sample)).toBe(true);
+  });
+
   test('returns false on single lettered option', () => {
     const sample = `
 A) Only one option mentioned in passing.