cistech-tunnel: move all scripts to dynamic mounts

- Move entrypoint.sh from build/scripts/ to shared/ (no longer baked into image)
- Add entrypoint directive to docker-compose.json pointing to /shared/entrypoint.sh
- Update entrypoint.sh to reference /shared/startup-vnc.sh instead of /opt/scripts/
- Bump tipi_version to 7

All scripts are now dynamically controlled via volume mounts from the shared/
directory. The Docker image is a clean base with only packages installed.

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

apps/cistech-tunnel/docker-compose.json

@@ -4,6 +4,7 @@
     {
       "name": "cistech-tunnel",
       "image": "git.alexzaw.dev/alexz/openconnect-vpn:latest",
+      "entrypoint": "/shared/entrypoint.sh",
       "environment": [
         {
           "key": "VPN_EMAIL",