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/ntfy/compose.yml

@@ -0,0 +1,30 @@
+services:
+  ntfy:
+    image: binwiederhier/ntfy:latest
+    container_name: ntfy
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:8080:80"
+    volumes:
+      - ntfy_cache:/var/cache/ntfy
+      - ntfy_data:/var/lib/ntfy
+    environment:
+      - NTFY_BASE_URL=https://ntfy.example.com
+      - NTFY_UPSTREAM=https://ntfy.sh
+      - NTFY_UPSTREAM_SUBSCRIBE_ENABLED=true
+    networks:
+      - ntfy-network
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:80/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 10s
+
+volumes:
+  ntfy_cache:
+  ntfy_data:
+
+networks:
+  ntfy-network:
+    driver: bridge