Enhance search functionality and indexing pipeline

- Updated `cmd_search` to include line numbers and content in search results.
- Modified `IndexingPipeline` to handle start and end line numbers for chunks.
- Enhanced `FTSEngine` to support storing line metadata in the database.
- Improved `SearchPipeline` to return line numbers and full content in search results.
- Added unit tests for bridge, FTS delete operations, metadata store, and watcher functionality.
- Introduced a `.gitignore` file to exclude specific directories.

codex-lens-v2/tests/unit/test_fts_delete.py

@@ -0,0 +1,66 @@
+"""Unit tests for FTSEngine delete_by_path and get_chunk_ids_by_path."""
+from __future__ import annotations
+
+import pytest
+
+from codexlens_search.search.fts import FTSEngine
+
+
+@pytest.fixture
+def fts(tmp_path):
+    return FTSEngine(str(tmp_path / "fts.db"))
+
+
+class TestGetChunkIdsByPath:
+    def test_empty(self, fts):
+        assert fts.get_chunk_ids_by_path("a.py") == []
+
+    def test_returns_matching_ids(self, fts):
+        fts.add_documents([
+            (0, "a.py", "hello world"),
+            (1, "a.py", "foo bar"),
+            (2, "b.py", "other content"),
+        ])
+        ids = fts.get_chunk_ids_by_path("a.py")
+        assert sorted(ids) == [0, 1]
+
+    def test_no_match(self, fts):
+        fts.add_documents([(0, "a.py", "content")])
+        assert fts.get_chunk_ids_by_path("b.py") == []
+
+
+class TestDeleteByPath:
+    def test_deletes_docs_and_meta(self, fts):
+        fts.add_documents([
+            (0, "target.py", "to be deleted"),
+            (1, "target.py", "also deleted"),
+            (2, "keep.py", "keep this"),
+        ])
+        count = fts.delete_by_path("target.py")
+        assert count == 2
+
+        # target.py gone from both tables
+        assert fts.get_chunk_ids_by_path("target.py") == []
+        assert fts.get_content(0) == ""
+        assert fts.get_content(1) == ""
+
+        # keep.py still there
+        assert fts.get_chunk_ids_by_path("keep.py") == [2]
+        assert fts.get_content(2) == "keep this"
+
+    def test_delete_nonexistent_path(self, fts):
+        count = fts.delete_by_path("nonexistent.py")
+        assert count == 0
+
+    def test_delete_then_search(self, fts):
+        fts.add_documents([
+            (0, "a.py", "unique searchable content"),
+            (1, "b.py", "different content here"),
+        ])
+        fts.delete_by_path("a.py")
+        results = fts.exact_search("unique searchable")
+        assert len(results) == 0
+
+        results = fts.exact_search("different")
+        assert len(results) == 1
+        assert results[0][0] == 1