Simplify ProfileDropdown logout logic by redirecting to /logout and update nginx.conf to restrict /logout to GET and POST methods only.

nginx.conf

@@ -40,6 +40,8 @@ http {
 
     # Full logout: clears local session and redirects to Keycloak logout
     location = /logout {
+      limit_except GET POST { deny all; }  # allow both GET and POST
+
       access_by_lua_block {
         local session = require("resty.session").start()
         session:destroy()