Fix forwarded client IP handling behind Coolify

[kingschnulli]

What changed

• resolve coolify-proxy from inside the Shopware container at boot
• trust only the resolved proxy IP(s) instead of Symfony's REMOTE_ADDR shortcut
• enable x-forwarded-for in addition to the existing proto/port headers
• regenerate the Shopware framework config only when the resolved proxy address changes
• clear Shopware cache after a trusted-proxy config change
• remove the static Compose-mounted proxy config

Why

The firewall uses Shopware/Symfony Request::getClientIp(). Without trusting X-Forwarded-For, external requests are reported as the Docker-side Traefik IP (for example 172.21.0.3), so blocking that address can affect multiple visitors. Trusting REMOTE_ADDR while enabling forwarded-for would also allow direct internal callers to spoof the forwarded client IP.