fix(hooks): recognize Prettier's TypeScript and JSON5 config files

Prettier's config searcher also reads .prettierrc.json5, .prettierrc.ts/.mts/.cts and prettier.config.ts/.mts/.cts. resolve-formatter knew none of them, so a project configured only through prettier.config.ts was never formatted by post-edit-format, quality-gate or the Stop batch. config-protection's rc pattern stopped at .yaml/.toml, so an existing .prettierrc.ts or .prettierrc.json5 could be edited freely.

tests/hooks/config-protection.test.js

@@ -447,6 +447,25 @@ function runTests() {
     })
   );
 
+  results.push(
+    test("blocks Prettier's TypeScript and JSON5 rc files", () => {
+      return withOwnedDirectory(fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-config-protect-prettier-')), tmpDir => {
+        for (const name of ['.prettierrc.ts', '.prettierrc.mts', '.prettierrc.cts', '.prettierrc.json5', '.prettierrc.shared.ts']) {
+          const absPath = path.join(tmpDir, name);
+          fs.writeFileSync(absPath, 'export default {};\n');
+
+          const result = runHook({ tool_name: 'Edit', tool_input: { file_path: absPath } });
+
+          assert.strictEqual(result.code, 2, 'Expected ' + name + ' to be blocked');
+          assert.ok(
+            result.stderr.includes('BLOCKED: Modifying ' + name + ' is not allowed.'),
+            'Expected block message for ' + name + ', got: ' + result.stderr
+          );
+        }
+      });
+    })
+  );
+
   results.push(
     test('does not block build or test tooling configs', () => {
       // Pins the boundary: this hook guards LINTER configs. A future widening

tests/lib/resolve-formatter.test.js

@@ -155,6 +155,21 @@ function runTests() {
     assert.strictEqual(detectFormatter(root), 'prettier');
   });
 
+  run("detectFormatter: detects Prettier's TypeScript and JSON5 config files", () => {
+    const names = ['.prettierrc.json5', '.prettierrc.ts', '.prettierrc.mts', '.prettierrc.cts',
+      'prettier.config.ts', 'prettier.config.mts', 'prettier.config.cts'];
+    for (const name of names) {
+      const root = makeTmpDir();
+      fs.writeFileSync(path.join(root, 'package.json'), JSON.stringify({ name: 'test' }));
+      fs.writeFileSync(path.join(root, name), 'export default {};\n');
+      assert.strictEqual(detectFormatter(root), 'prettier', name);
+      const nested = path.join(root, 'src');
+      fs.mkdirSync(nested);
+      fs.rmSync(path.join(root, 'package.json'));
+      assert.strictEqual(findProjectRoot(nested), root, `${name} marks the project root`);
+    }
+  });
+
   run('detectFormatter: detects prettier key in package.json', () => {
     const root = makeTmpDir();
     fs.writeFileSync(path.join(root, 'package.json'), JSON.stringify({ name: 'test', prettier: { singleQuote: true } }));