feat: Implement Cross-CLI Sync Panel for MCP servers

- Added CrossCliSyncPanel component for synchronizing MCP servers between Claude and Codex.
- Implemented server selection, copy operations, and result handling.
- Added tests for path mapping on Windows drives.
- Created E2E tests for ask_question Answer Broker functionality.
- Introduced MCP Tools Test Script for validating modified read_file and edit_file tools.
- Updated path_mapper to ensure correct drive formatting on Windows.
- Added .gitignore for ace-tool directory.

codex-lens/tests/test_path_mapper_windows_drive.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+import platform
+from pathlib import Path
+
+from codexlens.storage.path_mapper import PathMapper
+
+
+def test_denormalize_path_windows_drive_is_absolute() -> None:
+    if platform.system() != "Windows":
+        return
+
+    mapper = PathMapper(index_root=Path("C:/tmp/codexlens_indexes"))
+    mapped = mapper.denormalize_path("D/Claude_dms3/codex-lens/src")
+
+    assert mapped.is_absolute()
+    assert str(mapped).lower().startswith("d:\\") or str(mapped).lower().startswith("d:/")
+    assert mapped == Path("D:/Claude_dms3/codex-lens/src")
+

codex-lens/tests/test_stage1_binary_search_uses_chunk_lines.py

@@ -63,3 +63,69 @@ def test_stage1_binary_search_prefers_chunk_start_line(tmp_path: Path) -> None:
     finally:
         engine.close()
 
+
+def test_stage1_binary_search_dense_fallback(tmp_path: Path) -> None:
+    registry = RegistryStore(db_path=tmp_path / "registry.db")
+    registry.initialize()
+    mapper = PathMapper(index_root=tmp_path / "indexes")
+    engine = ChainSearchEngine(registry, mapper, config=Config(data_dir=tmp_path / "data"))
+
+    try:
+        index_root = tmp_path / "fake_index_root"
+        index_root.mkdir(parents=True, exist_ok=True)
+        index_db = index_root / "_index.db"
+        index_db.write_text("", encoding="utf-8")
+        (index_root / VECTORS_META_DB_NAME).write_text("", encoding="utf-8")
+
+        class _DummyEmbedder:
+            def embed_to_numpy(self, texts):
+                _ = texts
+                # Only dim matters for ANNIndex initialization
+                return [[0.0, 1.0, 2.0]]
+
+        class _DummyANNIndex:
+            def __init__(self, *args, **kwargs) -> None:
+                pass
+
+            def load(self) -> bool:
+                return True
+
+            def count(self) -> int:
+                return 1
+
+            def search(self, query_vec, top_k: int = 10):
+                _ = query_vec
+                _ = top_k
+                return [123], [0.2]
+
+        dummy_meta_store = MagicMock()
+        dummy_meta_store.get_chunks_by_ids.return_value = [
+            {
+                "chunk_id": 123,
+                "file_path": str(tmp_path / "b.py"),
+                "content": "def b():\n    return 2\n",
+                "start_line": 20,
+                "end_line": 22,
+                "metadata": {},
+                "category": "code",
+            }
+        ]
+
+        with patch.object(engine, "_get_centralized_binary_searcher", return_value=None):
+            with patch("codexlens.search.chain_search.VectorMetadataStore", return_value=dummy_meta_store):
+                with patch("codexlens.semantic.embedder.Embedder", return_value=_DummyEmbedder()):
+                    with patch("codexlens.semantic.ann_index.ANNIndex", _DummyANNIndex):
+                        coarse_results, returned_root = engine._stage1_binary_search(
+                            "b",
+                            [index_db],
+                            coarse_k=1,
+                            stats=SearchStats(),
+                        )
+
+        assert returned_root == index_root
+        assert len(coarse_results) == 1
+        assert coarse_results[0].start_line == 20
+        assert coarse_results[0].end_line == 22
+        assert coarse_results[0].score == 0.8
+    finally:
+        engine.close()