feat: move vault ssh signing into a plugin (C5)

docker/nginx-https.conf

@@ -267,7 +267,7 @@ http {
             proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
         }
 
-        location ~ ^/vault(/.*)?$ {
+        location = /vault/oidc/callback {
             proxy_pass http://127.0.0.1:30001;
             proxy_http_version 1.1;
             proxy_set_header Host $http_host;