[bug]: prime-cli compose sets WEBHOOK_ALLOWED_HOSTS from an undefined ${WEB_URL}, so the GitHub integration's Connect does nothing #10133

Version: Plane Commercial v3.3.3, Docker Compose, installed with prime-cli setup --behind-proxy, instance on a private IP.

Current behavior: The compose file prime-cli generates in /var/plane/docker-compose.yml has, on all five backend services:

WEB_URL: http://192.168.105.110
WEBHOOK_ALLOWED_HOSTS: ${WEB_URL}
WEBHOOK_ALLOWED_IPS: ""

WEB_URL is written as a literal service variable, but ${WEB_URL} is Compose interpolation, resolved from the shell or from a .env file next to the compose file, and prime-cli creates neither. WEBHOOK_ALLOWED_HOSTS is therefore empty. Even if it were set, WEB_URL holds a URL with a scheme, while WEBHOOK_ALLOWED_HOSTS expects comma-separated host names.

On an instance whose domain resolves to a private address, the SSRF guard introduced in #8884 then rejects the webhook Plane sends to its own Silo service when a workspace connects GitHub: clicking Connect in Workspace settings > Integrations > GitHub does nothing, and the internal webhook call fails with a 400.

Workaround: create /var/plane/.env with WEB_URL=<host>,<domain> (host names only), then prime-cli restart.

Expected behavior: prime-cli fills WEBHOOK_ALLOWED_HOSTS with the instance's host names, or the compose file takes them from a variable prime-cli defines.