Add Sonarr and Jellyfin widgets; reorder Media Server group

Sonarr shows wanted/queue/series, Jellyfin shows library blocks and
now-playing. SabNZBd and jDownloader moved to the end of Media Server.
Keys documented in .env.example.

.env.example

@@ -60,3 +60,15 @@ HOMEPAGE_VAR_HOMEASSISTANT_TOKEN=your-home-assistant-long-lived-access-token
 # is not a secret and is set directly in services.yaml as "client".
 HOMEPAGE_VAR_JDOWNLOADER_USERNAME=your-myjdownloader-email
 HOMEPAGE_VAR_JDOWNLOADER_PASSWORD=your-myjdownloader-password
+
+# --- SABnzbd widget ---
+# API key, found in SABnzbd under Config > General
+HOMEPAGE_VAR_SABNZBD_KEY=your-sabnzbd-api-key
+
+# --- Sonarr widget ---
+# API key, found in Sonarr under Settings > General
+HOMEPAGE_VAR_SONARR_KEY=your-sonarr-api-key
+
+# --- Jellyfin widget ---
+# API key, created in Jellyfin under Dashboard > Advanced > API Keys
+HOMEPAGE_VAR_JELLYFIN_KEY=your-jellyfin-api-key