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/wireguard/compose.yml

@@ -0,0 +1,26 @@
+services:
+  wireguard:
+    image: linuxserver/wireguard:latest
+    container_name: wireguard
+    restart: unless-stopped
+    cap_add:
+      - NET_ADMIN
+      - SYS_MODULE
+    volumes:
+      - wireguard_config:/config
+      - /lib/modules:/lib/modules
+    environment:
+      - PUID=1000
+      - PGID=1000
+      - TZ=UTC
+    networks:
+      - wireguard-network
+    sysctls:
+      - net.ipv4.conf.all.src_valid_mark=1
+
+volumes:
+  wireguard_config:
+
+networks:
+  wireguard-network:
+    driver: bridge