fix: move Astrolabe OAuth hook to before-starting for reliable OIDC client creation

Move 26-configure-astrolabe-oauth.sh from post-installation (runs once
on first boot) to before-starting (runs on every start). This ensures
the Astrolabe OIDC client is created as soon as MCP_SERVER_URL is
available, even if it wasn't set during initial installation.

Also copy 25-configure-mcp-server-url.sh to before-starting so the
mcp_server_url config stays current across container recreations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -47,6 +47,9 @@ services:
       - MYSQL_USER=nextcloud
       - MYSQL_HOST=db
       - REDIS_HOST=redis
+      # Set MCP_SERVER_URL to enable Astrolabe OAuth client auto-creation
+      # (before-starting hook creates OIDC client + stores credentials in config.php)
+      # Example: MCP_SERVER_URL=http://mcp-login-flow:8004 docker compose --profile login-flow up -d
       - MCP_SERVER_URL=${MCP_SERVER_URL:-}
     healthcheck:
       test: ["CMD-SHELL", "curl -Ss http://localhost/status.php | grep '\"installed\":true' || exit 1"]