Add FiltersHandler to server initialization to enable saved filters API endpoints.
Changes to cmd/server/main.go:
- Initialize filtersHandler using handlers.NewFiltersHandler(queries)
- Add FiltersHandler to Config struct for route registration
This enables the following API endpoints:
- GET /api/saved-filters?resource_type=X - List filters
- POST /api/saved-filters - Create filter
- PUT /api/saved-filters/:id - Update filter
- DELETE /api/saved-filters/:id - Delete filter
Part of saved filters feature implementation.