feat: add marketplace link when no parser available for file upload

Links to /home/market?category=Parser, same pattern as knowledge engine selector.

web/src/app/home/knowledge/components/kb-docs/FileUploadZone.tsx

@@ -1,4 +1,5 @@
 import React, { useCallback, useEffect, useState } from 'react';
+import { Link } from 'react-router-dom';
 import { Card, CardContent } from '@/components/ui/card';
 import {
   Select,
@@ -219,6 +220,12 @@ export default function FileUploadZone({
                 <p className="text-sm text-yellow-800 dark:text-yellow-200">
                   {t('knowledge.documentsTab.noParserAvailable')}
                 </p>
+                <Link
+                  to="/home/market?category=Parser"
+                  className="text-sm text-primary hover:underline mt-1 inline-block"
+                >
+                  {t('knowledge.documentsTab.installParserHint')}
+                </Link>
               </div>
             ) : (
               <div className="space-y-2">

web/src/i18n/locales/en-US.ts

@@ -872,6 +872,7 @@ const enUS = {
       builtInParser: 'Provided by Knowledge engine',
       noParserAvailable:
         'No parser supports this file type. Please install a parser plugin that can handle this format.',
+      installParserHint: 'Browse parser plugins in Marketplace →',
       confirmUpload: 'Upload',
       cancelUpload: 'Cancel',
     },

web/src/i18n/locales/zh-Hans.ts

@@ -832,6 +832,7 @@ const zhHans = {
       builtInParser: '由知识引擎提供',
       noParserAvailable:
         '没有解析器支持此文件类型，请安装支持该格式的解析器插件。',
+      installParserHint: '前往插件市场安装解析器 →',
       confirmUpload: '上传',
       cancelUpload: '取消',
     },

web/src/i18n/locales/zh-Hant.ts

@@ -825,6 +825,7 @@ const zhHant = {
       builtInParser: '由知識引擎提供',
       noParserAvailable:
         '沒有解析器支援此檔案類型，請安裝支援該格式的解析器插件。',
+      installParserHint: '前往插件市場安裝解析器 →',
       confirmUpload: '上傳',
       cancelUpload: '取消',
     },