feat(astrolabe): add admin search settings and enhanced UI
Add comprehensive admin controls for the unified search provider and enhance the frontend UI with filtering and visualization improvements.
**Admin Settings:**
- Configure default search algorithm (hybrid, semantic, bm25)
- Set fusion method for hybrid search (rrf, dbsf)
- Adjust minimum score threshold (0-100%)
- Set result limit (1-100 results)
**Frontend Enhancements:**
- Add score-based result filtering with slider control
- Add expandable excerpts for search results
- Improve result visualization and formatting
- Add algorithm badge to show search method used
**API Changes:**
- Add `/api/admin/search-settings` POST endpoint
- Add `searchForUnifiedSearch()` method to McpServerClient
- Load and apply admin settings in SemanticSearchProvider
**Technical Details:**
- Settings stored in app config table
- Defaults: hybrid algorithm, rrf fusion, 0% threshold, 20 results
- SemanticSearchProvider respects admin-configured limits
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Chris Coutinho
4cce4f6392