feat: Add stack.toml metadata files for Komodo recognition

Added stack.toml files for all stacks:
- monitoring/prometheus/stack.toml
- monitoring/grafana/stack.toml
- monitoring/node-exporter/stack.toml
- communication/gotify/stack.toml
- communication/vaultwarden/stack.toml

Each stack.toml contains:
- Stack metadata (name, description, version, category)
- Compose file reference
- Secret variables
- Port mappings
- Volume definitions
- Network configuration
- Healthcheck settings

stacks/communication/gotify/stack.toml

@@ -0,0 +1,29 @@
+[stack]
+name = "Gotify"
+description = "Push-Benachrichtigungen selbst gehostet"
+version = "1.0.0"
+category = "communication"
+
+[compose]
+file = "compose.yml"
+
+[variables.secrets]
+gotify-admin-user = "Admin Username"
+gotify-admin-pass = "Admin Password"
+
+[ports]
+internal = 80
+external = "127.0.0.1:9091"
+description = "Gotify Web UI"
+
+[volumes]
+gotify_data = "/app/data"
+
+[networks]
+gotify-network = "bridge"
+
+[healthcheck]
+endpoint = "http://localhost:80/health"
+interval = "30s"
+timeout = "10s"
+retries = 3