refactor(deployment): Remove WireGuard VPN dependency and restore public service access

Remove WireGuard integration from production deployment to simplify infrastructure:
- Remove docker-compose-direct-access.yml (VPN-bound services)
- Remove VPN-only middlewares from Grafana, Prometheus, Portainer
- Remove WireGuard middleware definitions from Traefik
- Remove WireGuard IPs (10.8.0.0/24) from Traefik forwarded headers

All monitoring services now publicly accessible via subdomains:
- grafana.michaelschiemer.de (with Grafana native auth)
- prometheus.michaelschiemer.de (with Basic Auth)
- portainer.michaelschiemer.de (with Portainer native auth)

All services use Let's Encrypt SSL certificates via Traefik.

deployment/ansible/wireguard/configs/michael-pc.conf

@@ -0,0 +1,14 @@
+[Interface]
+# Client: michael-pc
+# Generated: 2025-11-05T01:02:14Z
+PrivateKey = MHgxUzmEHQ15EB3v4TaXEcJAZNRaBd54/ZDcN6nN8lI=
+Address = 10.8.0.2/32
+DNS = 1.1.1.1, 8.8.8.8
+
+[Peer]
+# WireGuard Server
+PublicKey = SFxxHe4bunfQ1Xid5AMXbBgY+AjlxNtRHQ5uYjSib3E=
+PresharedKey = WsnvFp6WrF/y9fQwn3RgOTmwMS2UHoqIBRKrTPZ5lW8=
+Endpoint = 94.16.110.151:51820
+AllowedIPs = 10.8.0.0/24
+PersistentKeepalive = 25