feat: Add 10 new stacks (Batch 1)

Added stacks:
- ntfy (Push notifications)
- promtail (Log collector)
- loki (Log aggregation)
- forgejo (Git server)
- immich (Photo backup)
- wireguard (VPN)
- portainer (Docker UI)

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

stacks/portainer/compose.yml

@@ -0,0 +1,25 @@
+services:
+  portainer:
+    image: portainer/portainer-ce:latest
+    container_name: portainer
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:9000:9000"
+    volumes:
+      - portainer_data:/data
+      - /var/run/docker.sock:/var/run/docker.sock
+    networks:
+      - portainer-network
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:9000/api/version"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 30s
+
+volumes:
+  portainer_data:
+
+networks:
+  portainer-network:
+    driver: bridge