优化访客聊天窗口：展示消息时间并移除装饰蓝条

- 访客/客服气泡下方显示发送时间
- 去掉输入区顶部无用的蓝色渐变条

web/src/widgets/VisitorChat.tsx

@@ -466,7 +466,7 @@ const VisitorChat = ({
 
         {messages.map(msg => (
           msg.sender === 'visitor' ? (
-            <div key={msg.id} className="flex justify-end max-w-[85%] ml-auto">
+            <div key={msg.id} className="flex flex-col items-end max-w-[85%] ml-auto gap-1">
               <div className={`rounded-xl bg-[#2563eb] text-white text-[13px] leading-normal ${msg.type === 'image' ? 'p-1.5' : 'px-4 py-3'}`}>
                 {msg.type === 'image' ? (
                   <ChatImage src={msg.content} alt="图片" className="max-w-[180px] max-h-[180px]" />
@@ -474,17 +474,25 @@ const VisitorChat = ({
                   <p className="m-0 whitespace-pre-wrap break-words">{msg.content}</p>
                 )}
               </div>
+              {msg.time && (
+                <span className="text-[11px] text-neutral-400 pr-0.5">{msg.time}</span>
+              )}
             </div>
           ) : (
             <div key={msg.id} className="flex gap-2 max-w-[85%]">
               <div className="w-8 h-8 rounded-full bg-neutral-200 flex items-center justify-center shrink-0 mt-0.5">
                 <CustomerServiceOutlined className="text-xs text-neutral-500" />
               </div>
-              <div className={`rounded-xl bg-white border border-neutral-200 text-[13px] text-neutral-800 leading-normal ${msg.type === 'image' ? 'p-1.5' : 'px-4 py-3'}`}>
-                {msg.type === 'image' ? (
-                  <ChatImage src={msg.content} alt="图片" className="max-w-[180px] max-h-[180px]" />
-                ) : (
-                  <p className="m-0 whitespace-pre-wrap break-words">{msg.content}</p>
+              <div className="min-w-0 flex flex-col gap-1">
+                <div className={`rounded-xl bg-white border border-neutral-200 text-[13px] text-neutral-800 leading-normal ${msg.type === 'image' ? 'p-1.5' : 'px-4 py-3'}`}>
+                  {msg.type === 'image' ? (
+                    <ChatImage src={msg.content} alt="图片" className="max-w-[180px] max-h-[180px]" />
+                  ) : (
+                    <p className="m-0 whitespace-pre-wrap break-words">{msg.content}</p>
+                  )}
+                </div>
+                {msg.time && (
+                  <span className="text-[11px] text-neutral-400 pl-0.5">{msg.time}</span>
                 )}
               </div>
             </div>
@@ -509,11 +517,7 @@ const VisitorChat = ({
         <div ref={chatEndRef} />
       </section>
 
-      <footer className="shrink-0 relative px-4 py-3 bg-white border-t border-neutral-200">
-        <div
-          className="absolute top-0 left-0 right-0 h-[3px] pointer-events-none opacity-40"
-          style={{ background: 'linear-gradient(90deg, transparent 0%, #2563eb 50%, transparent 100%)' }}
-        />
+      <footer className="shrink-0 px-4 py-3 bg-white border-t border-neutral-200">
         {sendError && <div className="mb-2 text-xs text-red-500">{sendError}</div>}
 
         {!agentsOnline && !sessionEnded && (