feat: 添加文字输入对话功能

- 后端 WsQuery 添加 text 字段，支持文本输入模式
- Pipeline 支持文本查询时跳过 STT 直接使用输入文本
- 前端 ChatPanel 添加文字输入框，连接状态下可用
- useVisionSession 添加 sendTextMessage 方法
- 更新接口文档，添加文本输入模式说明

frontend/src/components/ChatPanel/index.tsx

@@ -1,9 +1,9 @@
 // ============================================================
 // ChatPanel — 消息展示面板
-// 职责：渲染对话消息列表、流式光标、元数据、自动滚动
+// 职责：渲染对话消息列表、流式光标、元数据、自动滚动、文本输入
 // ============================================================
 
-import { useEffect, useRef } from "react";
+import { useEffect, useRef, useState } from "react";
 import type { ChatMessage } from "../../types";
 import type { ConnectionStatus } from "../../lib/websocket";
 
@@ -11,12 +11,16 @@ interface ChatPanelProps {
   messages: ChatMessage[];
   currentReply?: string;
   connectionStatus: ConnectionStatus;
+  onSendText?: (text: string) => void;
 }
 
-export function ChatPanel({ messages, currentReply, connectionStatus }: ChatPanelProps) {
+export function ChatPanel({ messages, currentReply, connectionStatus, onSendText }: ChatPanelProps) {
   const bottomRef = useRef<HTMLDivElement>(null);
   const containerRef = useRef<HTMLDivElement>(null);
   const isAutoScroll = useRef(true);
+  const [inputText, setInputText] = useState("");
+
+  const isConnected = connectionStatus === "connected";
 
   // 用户上滚时暂停自动滚动，滚到底部时恢复
   useEffect(() => {
@@ -39,9 +43,17 @@ export function ChatPanel({ messages, currentReply, connectionStatus }: ChatPane
     }
   }, [messages, currentReply]);
 
+  // 提交文本消息
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    if (!inputText.trim() || !onSendText) return;
+    onSendText(inputText);
+    setInputText("");
+  };
+
   // 空状态
   if (messages.length === 0 && !currentReply) {
-    if (connectionStatus !== "connected") {
+    if (!isConnected) {
       return (
         <div className="chat-panel chat-panel--empty">
           <span className="chat-panel--empty-icon">💬</span>
@@ -60,35 +72,58 @@ export function ChatPanel({ messages, currentReply, connectionStatus }: ChatPane
   }
 
   return (
-    <div className="chat-panel" ref={containerRef}>
-      {messages.map((msg, index) => (
-        <div key={index} className={`chat-message chat-message--${msg.role}`}>
-          <div className="chat-message__role">
-            {msg.role === "user" ? "你" : "AI"}
-          </div>
-          <div className="chat-message__content">{msg.content}</div>
-          {msg.role === "assistant" && msg.tokensUsed !== undefined && (
-            <div className="chat-message__meta">
-              {msg.tokensUsed} tokens
-              {msg.latencyMs !== undefined && ` · ${(msg.latencyMs / 1000).toFixed(1)}s`}
-              {msg.model && ` · ${msg.model}`}
+    <div className="chat-panel">
+      <div className="chat-panel__messages" ref={containerRef}>
+        {messages.map((msg, index) => (
+          <div key={index} className={`chat-message chat-message--${msg.role}`}>
+            <div className="chat-message__role">
+              {msg.role === "user" ? "你" : "AI"}
             </div>
-          )}
-        </div>
-      ))}
-
-      {/* 流式回复（尚未完成） */}
-      {currentReply && (
-        <div className="chat-message chat-message--assistant chat-message--streaming">
-          <div className="chat-message__role">AI</div>
-          <div className="chat-message__content">
-            {currentReply}
-            <span className="cursor">▌</span>
+            <div className="chat-message__content">{msg.content}</div>
+            {msg.role === "assistant" && msg.tokensUsed !== undefined && (
+              <div className="chat-message__meta">
+                {msg.tokensUsed} tokens
+                {msg.latencyMs !== undefined && ` · ${(msg.latencyMs / 1000).toFixed(1)}s`}
+                {msg.model && ` · ${msg.model}`}
+              </div>
+            )}
           </div>
-        </div>
-      )}
+        ))}
 
-      <div ref={bottomRef} />
+        {/* 流式回复（尚未完成） */}
+        {currentReply && (
+          <div className="chat-message chat-message--assistant chat-message--streaming">
+            <div className="chat-message__role">AI</div>
+            <div className="chat-message__content">
+              {currentReply}
+              <span className="cursor">▌</span>
+            </div>
+          </div>
+        )}
+
+        <div ref={bottomRef} />
+      </div>
+
+      {/* 文本输入框 */}
+      {isConnected && onSendText && (
+        <form className="chat-input" onSubmit={handleSubmit}>
+          <input
+            type="text"
+            className="chat-input__field"
+            placeholder="输入文字对话..."
+            value={inputText}
+            onChange={(e) => setInputText(e.target.value)}
+          />
+          <button
+            type="submit"
+            className="chat-input__send"
+            disabled={!inputText.trim()}
+            title="发送"
+          >
+            ➤
+          </button>
+        </form>
+      )}
     </div>
   );
 }