test(install): add automated tests for user file preservation (#1423)

E2E tests verifying USER-PROFILE.md and dev-preferences.md survive
uninstall. Covers: profile preservation, preferences preservation,
engine files still removed, clean uninstall without user files.

Addresses review feedback requesting automated coverage for the
preserve-and-restore pattern in the rmSync uninstall path.

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

tests/copilot-install.test.cjs

@@ -1341,3 +1341,87 @@ describe('E2E: Copilot uninstall verification', () => {
     });
   });
 });
+
+// ─── Claude uninstall: user file preservation (#1423) ─────────────────────────
+
+function runClaudeInstall(cwd) {
+  const env = { ...process.env };
+  delete env.GSD_TEST_MODE;
+  return execFileSync(process.execPath, [INSTALL_PATH, '--claude', '--local'], {
+    cwd,
+    encoding: 'utf-8',
+    stdio: ['pipe', 'pipe', 'pipe'],
+    env,
+  });
+}
+
+function runClaudeUninstall(cwd) {
+  const env = { ...process.env };
+  delete env.GSD_TEST_MODE;
+  return execFileSync(process.execPath, [INSTALL_PATH, '--claude', '--local', '--uninstall'], {
+    cwd,
+    encoding: 'utf-8',
+    stdio: ['pipe', 'pipe', 'pipe'],
+    env,
+  });
+}
+
+describe('Claude uninstall preserves user-generated files (#1423)', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-preserve-'));
+    runClaudeInstall(tmpDir);
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  test('preserves USER-PROFILE.md across uninstall', () => {
+    const profilePath = path.join(tmpDir, '.claude', 'get-shit-done', 'USER-PROFILE.md');
+    const content = '# Developer Profile\n\nAutonomy: High\nGenerated: 2026-03-29\n';
+    fs.writeFileSync(profilePath, content);
+
+    runClaudeUninstall(tmpDir);
+
+    assert.ok(fs.existsSync(profilePath), 'USER-PROFILE.md should survive uninstall');
+    assert.strictEqual(fs.readFileSync(profilePath, 'utf-8'), content, 'content should be identical');
+  });
+
+  test('preserves dev-preferences.md across uninstall', () => {
+    const prefsPath = path.join(tmpDir, '.claude', 'commands', 'gsd', 'dev-preferences.md');
+    const content = '---\nname: dev-preferences\n---\n# Preferences\nUse TypeScript strict.\n';
+    fs.writeFileSync(prefsPath, content);
+
+    runClaudeUninstall(tmpDir);
+
+    assert.ok(fs.existsSync(prefsPath), 'dev-preferences.md should survive uninstall');
+    assert.strictEqual(fs.readFileSync(prefsPath, 'utf-8'), content, 'content should be identical');
+  });
+
+  test('still removes GSD engine files during uninstall', () => {
+    const profilePath = path.join(tmpDir, '.claude', 'get-shit-done', 'USER-PROFILE.md');
+    fs.writeFileSync(profilePath, '# Profile\n');
+
+    // Verify engine files exist before uninstall
+    const binDir = path.join(tmpDir, '.claude', 'get-shit-done', 'bin');
+    assert.ok(fs.existsSync(binDir), 'bin/ should exist before uninstall');
+
+    runClaudeUninstall(tmpDir);
+
+    // Engine files gone, user file preserved
+    assert.ok(!fs.existsSync(binDir), 'bin/ should be removed after uninstall');
+    assert.ok(fs.existsSync(profilePath), 'USER-PROFILE.md should survive');
+  });
+
+  test('clean uninstall when no user files exist', () => {
+    runClaudeUninstall(tmpDir);
+
+    const gsdDir = path.join(tmpDir, '.claude', 'get-shit-done');
+    const cmdDir = path.join(tmpDir, '.claude', 'commands', 'gsd');
+    // Directories should be fully removed when no user files to preserve
+    assert.ok(!fs.existsSync(gsdDir), 'get-shit-done/ should not exist after clean uninstall');
+    assert.ok(!fs.existsSync(cmdDir), 'commands/gsd/ should not exist after clean uninstall');
+  });
+});