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/loki/stack.toml

@@ -0,0 +1,4 @@
+[[stacks]]
+name = "loki"
+description = "Log Aggregation System"
+compose_path = "compose.yml"