LoreKeeper MCP

## Why The enhanced search specification requires case-insensitive name matching via `LOWER(name) = LOWER(?)` SQL queries, wildcard partial matching (`fire*`), and automatic slug fallback. However, the current implementation uses exact equality matching (`field = ?`) in the cache layer, making case-insensitive searches impossible at the database level. This is a critical gap (P0) that prevents the documented search features from working. ## What Changes - **BREAKING**: Modify cache query layer to support case-insensitive matching using `LOWER()` SQL function - Add `LOWER(name)` indexes to all entity tables for query performance - Implement wildcard detection and LIKE query generation in cache layer - Implement automatic slug fallback when name search returns no results - Add filter operators beyond simple equality (LIKE, case-insensitive) ## Impact - Affected specs: `database-setup`, `enhanced-search` - Affected code: - `src/lorekeeper_mcp/cache/db.py` - query_cached_entities() needs operator support - `src/lorekeeper_mcp/cache/schema.py` - add LOWER(name) index creation - `src/lorekeeper_mcp/repositories/base.py` - may need wildcard/fallback logic