feat: Flatten stack structure - all stacks directly in stacks/

- Removed all subdirectories
- Renamed compose.yml to <stack>-compose.yml
- Updated stack.toml to reference new compose file names
- Structure is now flat for easier Komodo sync

New structure:
stacks/
├── prometheus.toml
├── prometheus-compose.yml
├── grafana.toml
├── grafana-compose.yml
├── gotify.toml
├── gotify-compose.yml
├── vaultwarden.toml
├── vaultwarden-compose.yml
└── node-exporter.toml
└── node-exporter-compose.yml

stacks/prometheus/README.md

@@ -1,69 +0,0 @@
-# Prometheus
-
-📊 **Monitoring & Alerting**
-
-Prometheus ist ein Open-Source-Monitoring- und Alerting-System.
-
----
-
-## 🚀 Quick Start
-
-1. **In Komodo:** Stack auswählen → Deploy
-2. **Server wählen**
-3. **Warten** bis Container läuft
-4. **Caddy Config** hinzufügen
-5. **Öffnen** unter `prometheus.example.com`
-
----
-
-## 🔧 Caddy Integration
-
-```bash
-ssh <server>
-sudo nano /etc/caddy/Caddyfile
-```
-
-Hinzufügen:
-```caddyfile
-prometheus.example.com {
-    reverse_proxy localhost:9090
-}
-```
-
-```bash
-sudo systemctl reload caddy
-```
-
----
-
-## 🔐 Secrets (Komodo)
-
-Keine Secrets erforderlich für Basis-Installation.
-
----
-
-## 📁 Files
-
-- `compose.yml` - Docker Compose Konfiguration
-
----
-
-## 📊 Prometheus UI
-
-- **URL:** http://localhost:9090
-- **Query Browser:** `/graph`
-- **Alerts:** `/alerts`
-- **Targets:** `/targets`
-
----
-
-## 🔄 Updates
-
-Prometheus wird automatisch aktuell gehalten durch Komodo.
-
----
-
-## 📞 Support
-
-- **Docs:** https://prometheus.io/docs
-- **GitHub:** https://github.com/prometheus/prometheus