fix: improve CodexLens env defaults, self-exclusion, and route handling

- Adjust env defaults (embed batch 64, workers 2) and add HNSW/chunking params
- Exclude .codexlens directory from indexing and file watching
- Expand codexlens-routes with improved validation and error handling
- Enhance integration tests for broader route coverage

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -52,6 +52,7 @@ class TestWatcherConfig:
         assert ".git" in cfg.ignored_patterns
         assert "__pycache__" in cfg.ignored_patterns
         assert "node_modules" in cfg.ignored_patterns
+        assert ".codexlens" in cfg.ignored_patterns
 
     def test_custom(self):
         cfg = WatcherConfig(debounce_ms=1000, ignored_patterns={".custom"})