feat: Add 7 new stacks (Batch 2)

Added stacks:
- nextcloud-aio (Cloud storage)
- wordpress (CMS)
- searxng (Meta search)
- authentik (SSO provider)
- jellyfin (Media server)

All stacks include:
- compose.yml with proper configuration
- README.md with deployment info
- stack.toml for Komodo Resource Sync

stacks/jellyfin/compose.yml

@@ -0,0 +1,31 @@
+services:
+  jellyfin:
+    image: jellyfin/jellyfin:latest
+    container_name: jellyfin
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:8096:8096"
+    volumes:
+      - jellyfin_config:/config
+      - jellyfin_cache:/cache
+      - /media:/media:ro
+    devices:
+      - /dev/dri:/dev/dri
+    group_add:
+      - video
+    networks:
+      - jellyfin-network
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8096/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 30s
+
+volumes:
+  jellyfin_config:
+  jellyfin_cache:
+
+networks:
+  jellyfin-network:
+    driver: bridge