fix(ui): truncate long account emails in provider editor

- Add min-w-0 flex-1 for proper text overflow

- Add truncate class to prevent layout break

ui/src/components/cliproxy/provider-editor/account-item.tsx

@@ -187,9 +187,11 @@ export function AccountItem({
           >
             <User className="w-4 h-4" />
           </div>
-          <div>
+          <div className="min-w-0 flex-1">
             <div className="flex items-center gap-2">
-              <span className={cn('font-medium text-sm', privacyMode && PRIVACY_BLUR_CLASS)}>
+              <span
+                className={cn('font-medium text-sm truncate', privacyMode && PRIVACY_BLUR_CLASS)}
+              >
                 {account.email || account.id}
               </span>
               {account.isDefault && (