fix: multi-line TUI detection, stale scrollback, and false positives

The rate limit detection was fundamentally broken because Claude Code
renders rate limit messages across multiple lines in its TUI (Ink/React),
but all regex patterns required keywords on a single line.

Key fixes:
- Split detection into LIMIT_PATTERNS + RESET_PATTERNS with a 6-line
  sliding window, so multi-line TUI renders are detected correctly
- Capture only last 20 lines instead of 200 to avoid stale scrollback
- Add 30s post-retry cooldown to prevent re-detecting old messages
- Fix max-retries infinite loop (stay in waiting, check clear first)
- Add OSC/DCS sequence stripping for complete ANSI handling
- Parse relative times ("try again in 5 minutes") instead of 5h fallback
- Handle invalid timezones gracefully with fallback
- Fix zombie monitor on pane destruction (exit after 10 consecutive errors)
- Replace setInterval with recursive setTimeout to prevent concurrent ticks
- Restore user shell traps instead of clobbering them
- Remove overly broad /\blimit\b/ pattern that caused false positives

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/time-parser.test.js

@@ -31,6 +31,21 @@ describe('parseResetTime', () => {
   it('returns null for unparseable text', () => {
     assert.equal(parseResetTime('some random text'), null);
   });
+  it('parses "try again in 5 minutes" as relative time', () => {
+    const r = parseResetTime('try again in 5 minutes');
+    assert.ok(r.relative);
+    assert.equal(r.waitMs, 5 * 60_000);
+  });
+  it('parses "try again in 2 hours" as relative time', () => {
+    const r = parseResetTime('try again in 2 hours');
+    assert.ok(r.relative);
+    assert.equal(r.waitMs, 2 * 3_600_000);
+  });
+  it('parses "wait 30 mins" as relative time', () => {
+    const r = parseResetTime('wait 30 mins');
+    assert.ok(r.relative);
+    assert.equal(r.waitMs, 30 * 60_000);
+  });
 });
 
 describe('calculateWaitMs', () => {
@@ -59,4 +74,12 @@ describe('calculateWaitMs', () => {
     );
     assert.ok(wait > 0 && wait <= 3 * 3600_000);
   });
+  it('handles relative time correctly', () => {
+    const wait = calculateWaitMs({ relative: true, waitMs: 300_000 }, 60, 5);
+    assert.ok(Math.abs(wait - 360_000) < 2000); // 5 min + 60s margin
+  });
+  it('falls back on invalid timezone', () => {
+    const wait = calculateWaitMs({ hour: 15, minute: 0, timezone: 'Invalid/Zone' }, 60, 5);
+    assert.ok(Math.abs(wait - (5 * 3600 + 60) * 1000) < 2000); // fallback
+  });
 });