更新导航路径，修复确认按钮逻辑

src/pages/U4/u4.tsx

@@ -16,7 +16,7 @@ const U4: React.FC = () => {
   const navigate = useNavigate();
   const [test, setTest] = React.useState<testType[]>([]);
   const handleConfirm = () => {
-    navigate("/u5");
+    navigate("/UI6");
   };
   React.useEffect(() => {
     setTest([

src/pages/UI7/UI7.tsx

@@ -160,7 +160,8 @@ const UI6: React.FC = () => {
   const handleConfirm = () => {
     const canvas = canvasRef.current;
     if (!canvas) {
-      navigate("/UI7");
+      // navigate("/UI7");
+      alert("签名不能为空，请签名后再提交");
       return;
     }
 
@@ -178,7 +179,7 @@ const UI6: React.FC = () => {
       URL.revokeObjectURL(url);
     }, "image/png");
 
-    navigate("/UI7");
+    navigate("/UI8");
   };
 
   return (
@@ -270,7 +271,7 @@ const UI6: React.FC = () => {
           <div className="basic-confirm-section">
             <BackButton text="返回" onClick={handleBack} />
             {showWaitButton ? (
-              <WaitButton text={`等待(${countdown})S`} onClick={handleConfirm} />
+              <WaitButton text={`等待(${countdown})S`} />
             ) : (
               <ConfirmButton text="提交" onClick={handleConfirm} />
             )}