close the jellyfin ping-pong via mqtt webhook subscriber

after ffmpeg finishes we used to block the queue on a jellyfin refresh
+ re-analyze round-trip. now we just kick jellyfin and return. a new
mqtt subscriber listens for library events from jellyfin's webhook
plugin and re-runs upsertJellyfinItem — flipping plans back to pending
when the on-disk streams still don't match, otherwise confirming done.

- execute.ts: hand-off is fire-and-forget; no more sync re-analyze
- rescan.ts: upsertJellyfinItem takes source: 'scan' | 'webhook'.
  webhook-sourced rescans can reopen terminal 'done' plans when
  is_noop flips back to 0; scan-sourced rescans still treat done as
  terminal (keeps the dup-job fix from a06ab34 intact).
- mqtt.ts: long-lived client, auto-reconnect, status feed for UI badge
- webhook.ts: pure processWebhookEvent(db, deps) handler + 5s dedupe
  map to kill jellyfin's burst re-fires during library scans
- settings: /api/settings/mqtt{,/status,/test} + /api/settings/
  jellyfin/webhook-plugin (checks if the plugin is installed)
- ui: new Settings section with broker form, test button, copy-paste
  setup panel for the Jellyfin plugin template. MQTT status badge on
  the scan page.

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "netfelix-audio-fix",
-	"version": "2026.04.14.1",
+	"version": "2026.04.14.2",
 	"scripts": {
 		"dev:server": "NODE_ENV=development bun --hot server/index.tsx",
 		"dev:client": "vite",
@@ -17,6 +17,7 @@
 		"@tanstack/react-router": "^1.163.3",
 		"clsx": "^2.1.1",
 		"hono": "^4",
+		"mqtt": "^5.15.1",
 		"react": "19",
 		"react-aria-components": "^1.16.0",
 		"react-dom": "19",