refactor(cistech-tunnel): remove all systemd dependencies

- Dockerfile: Removed systemd, systemd-sysv, network-manager packages
- Dockerfile: Removed systemd service cleanup, vnc.service, cgroup volume
- docker-compose.json/yml: Removed /sys/fs/cgroup volume mount
- Bumped tipi_version to 4

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/cistech-tunnel/config.json

@@ -10,7 +10,7 @@
         "network"
     ],
     "description": "OpenConnect-SSO VPN running in an isolated namespace with noVNC for first-time SSO reconnects.",
-    "tipi_version": 3,
+    "tipi_version": 4,
     "version": "latest",
     "source": "local",
     "exposable": true,