feat(playground): enhance SSE debugging and add image paste support with i18n

- Add SSEViewer component for interactive SSE message inspection
  * Display SSE data stream with collapsible panels
  * Show parsed JSON with syntax highlighting
  * Display key information badges (content, tokens, finish reason)
  * Support copy individual or all SSE messages
  * Show error messages with detailed information

- Support Ctrl+V to paste images in chat input
  * Enable image paste in CustomInputRender component
  * Auto-detect and add pasted images to image list
  * Show toast notifications for paste results

- Add complete i18n support for 6 languages
  * Chinese (zh): Complete translations
  * English (en): Complete translations
  * Japanese (ja): Add 28 new translations
  * French (fr): Add 28 new translations
  * Russian (ru): Add 28 new translations
  * Vietnamese (vi): Add 32 new translations

- Update .gitignore to exclude data directory

web/src/hooks/playground/usePlaygroundState.js

@@ -18,8 +18,10 @@ For commercial licensing, please contact support@quantumnous.com
 */
 
 import { useState, useCallback, useRef, useEffect } from 'react';
+import { useTranslation } from 'react-i18next';
 import {
   DEFAULT_MESSAGES,
+  getDefaultMessages,
   DEFAULT_CONFIG,
   DEBUG_TABS,
   MESSAGE_STATUS,
@@ -33,9 +35,27 @@ import {
 import { processIncompleteThinkTags } from '../../helpers';
 
 export const usePlaygroundState = () => {
+  const { t } = useTranslation();
+  
   // 使用惰性初始化，确保只在组件首次挂载时加载配置和消息
   const [savedConfig] = useState(() => loadConfig());
-  const [initialMessages] = useState(() => loadMessages() || DEFAULT_MESSAGES);
+  const [initialMessages] = useState(() => {
+    const loaded = loadMessages();
+    // 检查是否是旧的中文默认消息，如果是则清除
+    if (loaded && loaded.length === 2 && loaded[0].id === '2' && loaded[1].id === '3') {
+      const hasOldChinese = 
+        loaded[0].content === '你好' || 
+        loaded[1].content === '你好，请问有什么可以帮助您的吗？' ||
+        loaded[1].content === '你好！很高兴见到你。有什么我可以帮助你的吗？';
+      
+      if (hasOldChinese) {
+        // 清除旧的默认消息
+        localStorage.removeItem('playground_messages');
+        return null;
+      }
+    }
+    return loaded;
+  });
 
   // 基础配置状态
   const [inputs, setInputs] = useState(
@@ -60,8 +80,16 @@ export const usePlaygroundState = () => {
   const [groups, setGroups] = useState([]);
   const [status, setStatus] = useState({});
 
-  // 消息相关状态 - 使用加载的消息初始化
-  const [message, setMessage] = useState(initialMessages);
+  // 消息相关状态 - 使用加载的消息或默认消息初始化
+  const [message, setMessage] = useState(() => initialMessages || getDefaultMessages(t));
+  
+  // 当语言改变时，如果是默认消息则更新
+  useEffect(() => {
+    // 只在没有保存的消息时才更新默认消息
+    if (!initialMessages) {
+      setMessage(getDefaultMessages(t));
+    }
+  }, [t, initialMessages]); // 当语言改变时
 
   // 调试状态
   const [debugData, setDebugData] = useState({
@@ -168,7 +196,7 @@ export const usePlaygroundState = () => {
     if (resetMessages) {
       setMessage([]);
       setTimeout(() => {
-        setMessage(DEFAULT_MESSAGES);
+        setMessage(getDefaultMessages(t));
       }, 0);
     }
   }, []);