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/components/playground/CustomRequestEditor.jsx

@@ -82,7 +82,7 @@ const CustomRequestEditor = ({
       return true;
     } catch (error) {
       setIsValid(false);
-      setErrorMessage(`JSON格式错误: ${error.message}`);
+      setErrorMessage(`${t('JSON格式错误')}: ${error.message}`);
       return false;
     }
   };
@@ -123,14 +123,14 @@ const CustomRequestEditor = ({
         <div className='flex items-center gap-2'>
           <Code size={16} className='text-gray-500' />
           <Typography.Text strong className='text-sm'>
-            自定义请求体模式
+            {t('自定义请求体模式')}
           </Typography.Text>
         </div>
         <Switch
           checked={customRequestMode}
           onChange={handleModeToggle}
-          checkedText='开'
-          uncheckedText='关'
+          checkedText={t('开')}
+          uncheckedText={t('关')}
           size='small'
         />
       </div>
@@ -140,7 +140,7 @@ const CustomRequestEditor = ({
           {/* 提示信息 */}
           <Banner
             type='warning'
-            description='启用此模式后，将使用您自定义的请求体发送API请求，模型配置面板的参数设置将被忽略。'
+            description={t('启用此模式后，将使用您自定义的请求体发送API请求，模型配置面板的参数设置将被忽略。')}
             icon={<AlertTriangle size={16} />}
             className='!rounded-lg'
             closeIcon={null}
@@ -150,21 +150,21 @@ const CustomRequestEditor = ({
           <div>
             <div className='flex items-center justify-between mb-2'>
               <Typography.Text strong className='text-sm'>
-                请求体 JSON
+                {t('请求体 JSON')}
               </Typography.Text>
               <div className='flex items-center gap-2'>
                 {isValid ? (
                   <div className='flex items-center gap-1 text-green-600'>
                     <Check size={14} />
                     <Typography.Text className='text-xs'>
-                      格式正确
+                      {t('格式正确')}
                     </Typography.Text>
                   </div>
                 ) : (
                   <div className='flex items-center gap-1 text-red-600'>
                     <X size={14} />
                     <Typography.Text className='text-xs'>
-                      格式错误
+                      {t('格式错误')}
                     </Typography.Text>
                   </div>
                 )}
@@ -177,7 +177,7 @@ const CustomRequestEditor = ({
                   disabled={!isValid}
                   className='!rounded-lg'
                 >
-                  格式化
+                  {t('格式化')}
                 </Button>
               </div>
             </div>
@@ -201,7 +201,7 @@ const CustomRequestEditor = ({
             )}
 
             <Typography.Text className='text-xs text-gray-500 mt-2 block'>
-              请输入有效的JSON格式的请求体。您可以参考预览面板中的默认请求体格式。
+              {t('请输入有效的JSON格式的请求体。您可以参考预览面板中的默认请求体格式。')}
             </Typography.Text>
           </div>
         </>