feat: 实现会话配置与多轮上下文

- 新增 ConfigPanel 组件：TTS 开关、detail level、语言选择
- 新增 storage.ts：配置持久化到 localStorage
- useVisionSession：连接后自动发送 config，维护最近 10 轮对话历史
- App：齿轮按钮展开配置面板，HD 角标，TTS 播放联动 ttsEnabled

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/App.css

@@ -53,6 +53,26 @@ body {
   font-weight: 700;
 }
 
+.header-right {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.btn-icon {
+  background: none;
+  border: none;
+  font-size: 1.2rem;
+  cursor: pointer;
+  padding: 4px;
+  border-radius: 4px;
+  transition: background 0.2s;
+}
+
+.btn-icon:hover {
+  background: var(--color-surface);
+}
+
 .status {
   font-size: 0.85rem;
   padding: 4px 12px;
@@ -364,3 +384,67 @@ body {
 @keyframes spin {
   to { transform: rotate(360deg); }
 }
+
+/* ---- Config Panel ---- */
+
+.config-panel {
+  background: var(--color-surface);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius);
+  padding: 16px;
+  margin: 8px 0;
+}
+
+.config-panel__header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 12px;
+  font-weight: 600;
+}
+
+.config-panel__close {
+  background: none;
+  border: none;
+  color: var(--color-text-muted);
+  cursor: pointer;
+  font-size: 1rem;
+  padding: 2px 6px;
+}
+
+.config-panel__close:hover {
+  color: var(--color-text);
+}
+
+.config-row {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 8px 0;
+  font-size: 0.9rem;
+}
+
+.config-row select,
+.config-row input[type="checkbox"] {
+  background: var(--color-bg);
+  color: var(--color-text);
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  padding: 4px 8px;
+  font-size: 0.85rem;
+}
+
+/* ---- Detail Badge ---- */
+
+.detail-badge {
+  position: absolute;
+  top: 8px;
+  right: 8px;
+  background: rgba(37, 99, 235, 0.8);
+  color: white;
+  padding: 2px 8px;
+  border-radius: 4px;
+  font-size: 0.7rem;
+  font-weight: 700;
+  letter-spacing: 0.5px;
+}

frontend/src/App.tsx

@@ -2,13 +2,17 @@
 // CamTalk — 主应用组件
 // ============================================================
 
+import { useState } from "react";
 import { useVisionSession } from "./hooks/useVisionSession";
 import { VideoPreview } from "./components/VideoPreview";
 import { ChatPanel } from "./components/ChatPanel";
+import { ConfigPanel } from "./components/ConfigPanel";
 import { ToastContainer } from "./components/Toast";
 import "./App.css";
 
 function App() {
+  const [showConfig, setShowConfig] = useState(false);
+
   const {
     messages,
     currentReply,
@@ -20,6 +24,8 @@ function App() {
     connectionStatus,
     videoRef,
     stream,
+    config,
+    updateConfig,
     startSession,
     stopSession,
     interrupt,
@@ -31,6 +37,7 @@ function App() {
     <div className="app">
       <header className="app-header">
         <h1>CamTalk</h1>
+        <div className="header-right">
           <span className={`status status--${connectionStatus}`}>
             {isConnected
               ? "已连接"
@@ -38,13 +45,36 @@ function App() {
                 ? "连接中..."
                 : "未连接"}
           </span>
+          {isConnected && (
+            <button
+              className="btn-icon"
+              onClick={() => setShowConfig((v) => !v)}
+              title="设置"
+            >
+              ⚙️
+            </button>
+          )}
+        </div>
       </header>
 
+      {showConfig && (
+        <ConfigPanel
+          config={config}
+          onUpdate={updateConfig}
+          onClose={() => setShowConfig(false)}
+        />
+      )}
+
       <main className="app-main">
         <div className="video-section">
           <VideoPreview ref={videoRef} isStreaming={!!stream} />
+          {config.detailLevel === "high" && (
+            <div className="detail-badge">HD</div>
+          )}
           {isSpeaking && <div className="vad-indicator">🎤 正在聆听...</div>}
-          {isAudioPlaying && <div className="vad-indicator vad-indicator--audio">🔊 正在播放...</div>}
+          {isAudioPlaying && config.ttsEnabled && (
+            <div className="vad-indicator vad-indicator--audio">🔊 正在播放...</div>
+          )}
           {isConnected && !isVADReady && !vadError && (
             <div className="vad-indicator vad-indicator--loading">
               正在初始化语音检测...

frontend/src/components/ConfigPanel/index.tsx

@@ -0,0 +1,55 @@
+// ============================================================
+// ConfigPanel — 会话配置面板
+// 职责：TTS 开关、detail level 切换、语言选择
+// ============================================================
+
+import type { SessionConfig } from "../../types";
+
+interface ConfigPanelProps {
+  config: SessionConfig;
+  onUpdate: (partial: Partial<SessionConfig>) => void;
+  onClose: () => void;
+}
+
+export function ConfigPanel({ config, onUpdate, onClose }: ConfigPanelProps) {
+  return (
+    <div className="config-panel">
+      <div className="config-panel__header">
+        <span>设置</span>
+        <button className="config-panel__close" onClick={onClose}>✕</button>
+      </div>
+
+      <label className="config-row">
+        <span>语音回答</span>
+        <input
+          type="checkbox"
+          checked={config.ttsEnabled}
+          onChange={(e) => onUpdate({ ttsEnabled: e.target.checked })}
+        />
+      </label>
+
+      <label className="config-row">
+        <span>图像精度</span>
+        <select
+          value={config.detailLevel}
+          onChange={(e) => onUpdate({ detailLevel: e.target.value as "low" | "high" })}
+        >
+          <option value="low">低（省流量）</option>
+          <option value="high">高（细节丰富）</option>
+        </select>
+      </label>
+
+      <label className="config-row">
+        <span>语言</span>
+        <select
+          value={config.language}
+          onChange={(e) => onUpdate({ language: e.target.value })}
+        >
+          <option value="zh-CN">中文</option>
+          <option value="en-US">English</option>
+          <option value="ja-JP">日本語</option>
+        </select>
+      </label>
+    </div>
+  );
+}

frontend/src/hooks/useVisionSession.ts

@@ -11,17 +11,24 @@ import { encodeAudioToBase64, dataUrlToBase64 } from "../lib/audio";
 import { getErrorMessage } from "../lib/errors";
 import { TTSPlayer } from "../lib/ttsPlayer";
 import { showToast } from "../lib/toast";
+import { loadConfig, saveConfig } from "../lib/storage";
 import { useCamera } from "../components/CameraManager";
 import { useMicrophone } from "../components/MicManager";
 import { useVAD } from "../components/EdgeProcessor";
 import { useWebSocketManager } from "../components/WebSocketManager";
-import type { ChatMessage, ServerMessage, LLMDoneMessage } from "../types";
+import type { ChatMessage, SessionConfig, ServerMessage, LLMDoneMessage } from "../types";
+
+const MAX_HISTORY_ROUNDS = 10;
 
 export function useVisionSession() {
   const [messages, setMessages] = useState<ChatMessage[]>([]);
   const [currentReply, setCurrentReply] = useState<string>("");
   const [isProcessing, setIsProcessing] = useState(false);
   const [isAudioPlaying, setIsAudioPlaying] = useState(false);
+  const [config, setConfig] = useState<SessionConfig>(loadConfig);
+
+  // 对话历史（role + content），用于多轮上下文
+  const historyRef = useRef<Array<{ role: string; content: string }>>([]);
 
   // TTS 播放器
   const ttsPlayerRef = useRef<TTSPlayer | null>(null);
@@ -44,6 +51,40 @@ export function useVisionSession() {
     isProcessingRef.current = isProcessing;
   }, [isProcessing]);
 
+  // WebSocket 连接成功后发送 config
+  useEffect(() => {
+    if (status === "connected") {
+      send({
+        type: "config",
+        payload: {
+          tts_enabled: config.ttsEnabled,
+          detail_level: config.detailLevel,
+          language: config.language,
+        },
+      });
+    }
+  }, [status]); // eslint-disable-line react-hooks/exhaustive-deps -- 仅在连接状态变化时发送
+
+  /** 更新会话配置 */
+  const updateConfig = useCallback((partial: Partial<SessionConfig>) => {
+    setConfig((prev) => {
+      const next = { ...prev, ...partial };
+      saveConfig(next);
+      // 如果已连接，立即发送更新
+      if (status === "connected") {
+        send({
+          type: "config",
+          payload: {
+            tts_enabled: next.ttsEnabled,
+            detail_level: next.detailLevel,
+            language: next.language,
+          },
+        });
+      }
+      return next;
+    });
+  }, [status, send]);
+
   // VAD：语音结束时自动发送 query
   const {
     isSpeaking,
@@ -111,6 +152,13 @@ export function useVisionSession() {
 
         case "llm_done": {
           const done = msg as LLMDoneMessage;
+          // 记录到对话历史
+          historyRef.current.push({ role: "assistant", content: done.full_text });
+          // 裁剪历史到最近 N 轮
+          if (historyRef.current.length > MAX_HISTORY_ROUNDS * 2) {
+            historyRef.current = historyRef.current.slice(-MAX_HISTORY_ROUNDS * 2);
+          }
+
           setMessages((prev) => [
             ...prev,
             {
@@ -145,14 +193,6 @@ export function useVisionSession() {
     return unsub;
   }, [getTTSPlayer]);
 
-  // 连接断开时显示提示
-  useEffect(() => {
-    if (status === "disconnected") {
-      // 只在非主动断开时提示（通过检查是否有活跃会话判断）
-      // 这里简单处理，由 App 层根据状态显示
-    }
-  }, [status]);
-
   /** 启动会话 */
   const startSession = useCallback(async () => {
     // 1. 获取摄像头和麦克风
@@ -182,6 +222,7 @@ export function useVisionSession() {
     setMessages([]);
     setCurrentReply("");
     setIsProcessing(false);
+    historyRef.current = [];
   }, [stopVAD, stopMic, stopCamera, disconnect]);
 
   /** 打断当前回复 */
@@ -192,9 +233,11 @@ export function useVisionSession() {
     setIsAudioPlaying(false);
     // 将未完成的流式内容保存为最终消息
     if (currentReply) {
+      const interrupted = currentReply + "（已打断）";
+      historyRef.current.push({ role: "assistant", content: interrupted });
       setMessages((prev) => [
         ...prev,
-        { role: "assistant", content: currentReply + "（已打断）", timestamp: Date.now() },
+        { role: "assistant", content: interrupted, timestamp: Date.now() },
       ]);
     }
     setCurrentReply("");
@@ -212,6 +255,8 @@ export function useVisionSession() {
     connectionStatus: status,
     videoRef,
     stream,
+    config,
+    updateConfig,
     startSession,
     stopSession,
     interrupt,

frontend/src/lib/storage.ts

@@ -0,0 +1,35 @@
+// ============================================================
+// Storage — localStorage 封装
+// 职责：会话配置持久化
+// ============================================================
+
+import type { SessionConfig } from "../types";
+
+const CONFIG_KEY = "camtalk:config";
+
+const DEFAULT_CONFIG: SessionConfig = {
+  ttsEnabled: true,
+  detailLevel: "low",
+  language: "zh-CN",
+};
+
+/** 加载配置，无存储时返回默认值 */
+export function loadConfig(): SessionConfig {
+  try {
+    const raw = localStorage.getItem(CONFIG_KEY);
+    if (!raw) return DEFAULT_CONFIG;
+    const parsed = JSON.parse(raw) as Partial<SessionConfig>;
+    return { ...DEFAULT_CONFIG, ...parsed };
+  } catch {
+    return DEFAULT_CONFIG;
+  }
+}
+
+/** 保存配置到 localStorage */
+export function saveConfig(config: SessionConfig): void {
+  try {
+    localStorage.setItem(CONFIG_KEY, JSON.stringify(config));
+  } catch {
+    // localStorage 不可用时静默失败
+  }
+}