- Added Kagi Universal Summarizer integration for URL and YouTube video summarization with fallback support.
- Exported `searchWithKagi` and `summarizeUrlWithKagi` functions from new shared `web/kagi` module for reuse across components.
- Changed HTML-to-text rendering priority to attempt Kagi summarization first before Jina, Trafilatura, and Lynx.
- Refactored Kagi search provider to use shared utilities from `web/kagi` module, reducing code duplication.
- Added `KagiApiError` exception class for Kagi API-specific error handling with optional status code tracking.