Add Plex and Jellyfin webhook integration for automatic watch tracking

When a user finishes watching on their media server, a webhook fires and
Sofa logs it as watched, triggering all existing auto-transitions. Each
user configures their connection in settings and gets a unique webhook URL.

- Add webhookConnections and webhookEventLog schema tables
- Add TMDB findByExternalId for resolving IMDB/TVDB IDs
- Add source parameter to tracking functions (plex/jellyfin)
- Add webhook processing service with payload parsers, title resolution,
  and deduplication
- Add public webhook receiver route (token-based auth)
- Add authenticated settings API routes for managing connections
- Add Media Servers section to settings UI with Plex/Jellyfin cards

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

drizzle/20260301210600_minor_karnak/migration.sql

@@ -0,0 +1,27 @@
+CREATE TABLE `webhookConnections` (
+	`id` text PRIMARY KEY,
+	`userId` text NOT NULL,
+	`provider` text NOT NULL,
+	`token` text NOT NULL,
+	`mediaServerUsername` text NOT NULL,
+	`enabled` integer DEFAULT true NOT NULL,
+	`createdAt` integer NOT NULL,
+	`lastEventAt` integer,
+	CONSTRAINT `fk_webhookConnections_userId_user_id_fk` FOREIGN KEY (`userId`) REFERENCES `user`(`id`) ON DELETE CASCADE
+);
+--> statement-breakpoint
+CREATE TABLE `webhookEventLog` (
+	`id` text PRIMARY KEY,
+	`connectionId` text NOT NULL,
+	`eventType` text,
+	`mediaType` text,
+	`mediaTitle` text,
+	`status` text NOT NULL,
+	`errorMessage` text,
+	`receivedAt` integer NOT NULL,
+	CONSTRAINT `fk_webhookEventLog_connectionId_webhookConnections_id_fk` FOREIGN KEY (`connectionId`) REFERENCES `webhookConnections`(`id`) ON DELETE CASCADE
+);
+--> statement-breakpoint
+CREATE UNIQUE INDEX `webhookConnections_userId_provider` ON `webhookConnections` (`userId`,`provider`);--> statement-breakpoint
+CREATE UNIQUE INDEX `webhookConnections_token` ON `webhookConnections` (`token`);--> statement-breakpoint
+CREATE INDEX `webhookEventLog_connectionId_receivedAt` ON `webhookEventLog` (`connectionId`,`receivedAt`);