feat(core): enable search hidden dir

evals/grep_search_functionality.eval.ts

@@ -179,4 +179,24 @@ describe('grep_search_functionality', () => {
       });
     },
   });
+
+  evalTest('USUALLY_PASSES', {
+    suiteName: 'default',
+    suiteType: 'behavioral',
+    name: 'should find files in hidden directories',
+    files: {
+      '.hidden_dir/system.md':
+        'Instructional Conversion and Integration Protocol',
+      'visible_dir/normal.txt': 'nothing to see here',
+    },
+    prompt: 'Find "Instructional Conversion and Integration Protocol"',
+    assert: async (rig: TestRig, result: string) => {
+      await rig.waitForToolCall('grep_search');
+      assertModelHasOutput(result);
+      checkModelOutputContent(result, {
+        expectedContent: [/\.hidden_dir\/system\.md/],
+        testName: `${TEST_PREFIX}hidden directory search`,
+      });
+    },
+  });
 });