- Updated `search_code` function to include a `quality` parameter for search quality tiers: "fast", "balanced", "thorough", and "auto".
- Introduced `search_scope` function to limit search results to a specific directory scope.
- Added `index_scope` function for indexing a specific directory without re-indexing the entire project.
- Refactored `SearchPipeline` to support quality-based routing in the `search` method.
- Implemented `Shard` and `ShardManager` classes to manage multiple index shards with LRU eviction and efficient file routing.
- Added debounce functionality in `IncrementalIndexer` to batch file events and reduce redundant processing.
- Enhanced `FileWatcher` to integrate with `IncrementalIndexer` for improved event handling.