test: add regression test for phantom milestone ghost detection

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

src/resources/extensions/gsd/tests/phantom-ghost-detection.test.ts

@@ -0,0 +1,55 @@
+/**
+ * Regression test for #3671 — isGhostMilestone detects phantom queued rows
+ *
+ * gsd_milestone_generate_id inserts a DB row with status "queued" as a side
+ * effect. If the milestone is never planned, isGhostMilestone previously
+ * returned false for any milestone with a DB row, blocking the state machine.
+ *
+ * The fix makes isGhostMilestone treat a "queued" DB row with no disk
+ * artifacts (CONTEXT, ROADMAP, SUMMARY) as a ghost.
+ *
+ * This structural test verifies the dbRow.status === 'queued' guard exists.
+ */
+
+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, '..', 'state.ts'), 'utf-8');
+
+describe('isGhostMilestone phantom queued detection (#3671)', () => {
+  test('isGhostMilestone function exists', () => {
+    assert.match(source, /export function isGhostMilestone\(/,
+      'isGhostMilestone should be exported');
+  });
+
+  test('checks dbRow.status === queued', () => {
+    assert.match(source, /dbRow\.status\s*===\s*['"]queued['"]/,
+      'isGhostMilestone should check dbRow.status === "queued"');
+  });
+
+  test('checks for CONTEXT disk artifact', () => {
+    assert.match(source, /resolveMilestoneFile\(basePath,\s*mid,\s*["']CONTEXT["']\)/,
+      'should check for CONTEXT file');
+  });
+
+  test('checks for ROADMAP disk artifact', () => {
+    assert.match(source, /resolveMilestoneFile\(basePath,\s*mid,\s*["']ROADMAP["']\)/,
+      'should check for ROADMAP file');
+  });
+
+  test('checks for SUMMARY disk artifact', () => {
+    assert.match(source, /resolveMilestoneFile\(basePath,\s*mid,\s*["']SUMMARY["']\)/,
+      'should check for SUMMARY file');
+  });
+
+  test('returns !hasContent for queued rows (ghost if no artifacts)', () => {
+    assert.match(source, /return !hasContent/,
+      'should return !hasContent for queued phantom milestones');
+  });
+});