feat: Jellyfin/Plex auto-import via watch queue

Webhook ingestion from media servers — movies land in a pending
watch queue, user rates and confirms to create diary entries.

- domain: WatchEvent, WebhookToken models, MediaServerParser port
- adapters: jellyfin + plex parser crates, SQLite + Postgres repos
- application: ingest/confirm/dismiss/cleanup use cases, token mgmt
- presentation: webhook endpoints (bearer + query param auth),
  watch queue + integrations settings HTML pages, OpenAPI docs
- worker: WatchEventCleanupJob (daily, 30d retention)

Movie resolution deferred to confirm — single canonical path
through log_review for enrichment, poster fetch, federation.

crates/presentation/src/handlers/mod.rs

@@ -3,6 +3,7 @@ pub mod html;
 pub mod images;
 pub mod import;
 pub mod rss;
+pub mod webhook;
 
 const DEFAULT_PAGE_LIMIT: u32 = 5;
 const RSS_FEED_LIMIT: u32 = 50;