Add Sonarr and Radarr list integrations

- New `lists` service fetches Sonarr/Radarr library via their REST APIs
  and auto-imports matching titles from TMDB into the user's watchlist
- `app/api/lists/[token]/route.ts` webhook endpoint triggers a list sync
- Unified `IntegrationCard` component replaces `WebhookCard`, handling
  both webhook-style (Plex/Jellyfin/Emby) and list-style (Sonarr/Radarr)
  integrations with per-type config forms
- Schema migration adds `sonarr` and `radarr` to the integration type
  enum and a `listConnections` table for list-based integrations
- 212 tests added for the lists service covering import, deduplication,
  and error handling

lib/tmdb/types.ts

@@ -61,9 +61,15 @@ export interface TmdbTvDetails {
   content_ratings?: {
     results: { iso_3166_1: string; rating: string }[];
   };
+  external_ids?: TmdbExternalIds;
   seasons: TmdbSeasonSummary[];
 }
 
+export interface TmdbExternalIds {
+  tvdb_id: number | null;
+  imdb_id: string | null;
+}
+
 export interface TmdbSeasonSummary {
   id: number;
   season_number: number;