feat: self-hosted GitLab Apps OAuth integration

Adds self-hosted GitLab OAuth sources so Coolify can connect to a self-managed GitLab instance, list private repositories, clone over an OAuth token, and deploy (the GitLab counterpart to GitHub Apps).

Hardening: authenticated, one-time team-bound OAuth callback state; token redaction in deploy logs; custom host port/path kept in clone and ls-remote URLs; submodule OAuth auth; system-wide source selection. Covered by unit and feature tests.

cosigned by OpenAI Codex at M1 Max

bootstrap/helpers/remoteProcess.php

@@ -301,6 +301,7 @@ function remove_iip($text)
 
     // Git access tokens
     $text = preg_replace('/x-access-token:.*?(?=@)/', 'x-access-token:'.REDACTED, $text);
+    $text = preg_replace('/oauth2:.*?(?=@)/', 'oauth2:'.REDACTED, $text);
 
     // ANSI color codes
     $text = preg_replace('/\x1b\[[0-9;]*m/', '', $text);