feat(contacts): implement pagination, search, and sorting for contacts API

- Enhanced the `/api/contacts` endpoint to support pagination, allowing users to specify `page` and `page_size` parameters.
- Added search functionality to filter contacts based on a search term.
- Implemented sorting options for the contacts list, enabling users to sort by various fields.
- Updated the frontend to reflect these changes, including a new pagination UI and improved loading states.
- Introduced caching for multibyte hop chunks to optimize performance when retrieving contact badge evidence.
- Added tests to ensure the new features work as expected and maintain existing functionality.

docs/web-viewer.md

@@ -193,7 +193,9 @@ proxy_set_header X-Forwarded-Proto $scheme;
 The viewer also provides JSON API endpoints:
 
 - `GET /api/stats` - Database statistics
-- `GET /api/contacts` - Repeater contacts data
+- `GET /api/contacts` - Repeater contacts data. The contacts page uses optional
+  `page`, `page_size` (maximum 200), `search`, `sort`, and `direction` parameters;
+  callers that omit pagination retain the legacy full-list response.
 - `GET /api/tracking` - Contact tracking data
 
 Example usage: