feat(branding): add global dynamic theme system and fix 2fa mail

shop/components/login-form.tsx

@@ -137,8 +137,11 @@ export function LoginForm({
     }
   };
 
+  const isVerifyingRef = useRef(false);
+
   const handleVerify2FA = async (code: string) => {
-    if (!userId) return;
+    if (!userId || isVerifyingRef.current) return;
+    isVerifyingRef.current = true;
     setIsLoading(true);
     setError(null);
 
@@ -160,6 +163,7 @@ export function LoginForm({
       inputRefs.current[0]?.focus();
     } finally {
       setIsLoading(false);
+      isVerifyingRef.current = false;
     }
   };