test: add regression test for run-uat replay cap

Structural verification that MAX_UAT_ATTEMPTS constant exists and
incrementUatCount is called before dispatch (#3624).

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

src/resources/extensions/gsd/tests/run-uat-replay-cap.test.ts

@@ -0,0 +1,51 @@
+/**
+ * Regression test for #3624 — cap run-uat dispatch attempts
+ *
+ * When verification commands fail before writing a verdict, the run-uat
+ * dispatch rule fires repeatedly in an infinite loop. The fix adds a
+ * MAX_UAT_ATTEMPTS constant and calls incrementUatCount before dispatch
+ * to cap the number of attempts.
+ *
+ * Structural verification test — reads source to confirm MAX_UAT_ATTEMPTS
+ * and incrementUatCount exist.
+ */
+
+import { describe, test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import { dirname, join } from 'node:path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+const source = readFileSync(join(__dirname, '..', 'auto-dispatch.ts'), 'utf-8');
+
+describe('run-uat replay cap (#3624)', () => {
+  test('MAX_UAT_ATTEMPTS constant is defined', () => {
+    assert.match(source, /const MAX_UAT_ATTEMPTS\s*=\s*\d+/,
+      'MAX_UAT_ATTEMPTS constant should be defined');
+  });
+
+  test('incrementUatCount function is exported', () => {
+    assert.match(source, /export function incrementUatCount\(/,
+      'incrementUatCount should be an exported function');
+  });
+
+  test('getUatCount function is exported', () => {
+    assert.match(source, /export function getUatCount\(/,
+      'getUatCount should be an exported function');
+  });
+
+  test('incrementUatCount is called before dispatch in rule', () => {
+    // incrementUatCount should be called before the dispatch return
+    const ruleSection = source.slice(source.indexOf('checkNeedsRunUat'));
+    assert.match(ruleSection, /incrementUatCount\(/,
+      'incrementUatCount should be called in the dispatch rule');
+  });
+
+  test('attempts are compared against MAX_UAT_ATTEMPTS', () => {
+    assert.match(source, /attempts\s*>\s*MAX_UAT_ATTEMPTS/,
+      'dispatch should check attempts > MAX_UAT_ATTEMPTS');
+  });
+});