fix(deploy): add auth proxy configuration for phpMyAdmin

Include auth_request and upstream_status directives in
nginx location block to enable authentication proxy
for phpMyAdmin access.

docs/deploy.md

@@ -61,6 +61,9 @@ server {
     include /etc/nginx/snippets/auth-proxy.conf;
 
     location / {
+        auth_request /_auth_proxy;
+        auth_request_set $auth_status $upstream_status;
+
         proxy_pass http://phpmyadmin:80/;
         # ... other proxy settings ...
     }