Localizza errori API, sistema layout mobile e documenta allineamento iOS.

Gli header Accept-Language dalle app e i fix di padding/menu sul web chiudono il giro password-policy; il doc guida il lavoro su Mac.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/views/shared/_language_switcher.html.erb

@@ -58,10 +58,18 @@
   }
 
   toggle.addEventListener("click", function (e) {
+    e.preventDefault();
     e.stopPropagation();
     setOpen(menu.hidden);
   });
 
+  // Keep parent mobile nav open while interacting with the switcher UI.
+  root.addEventListener("click", function (e) {
+    if (e.target.closest(".lang-switcher__toggle")) {
+      e.stopPropagation();
+    }
+  });
+
   document.addEventListener("click", function (e) {
     if (!root.contains(e.target)) setOpen(false);
   });