feat: add web entry to download desktop client

frontend/app.js

@@ -271,6 +271,8 @@ createApp({
         error: '',
         lastLoadedAt: ''
       },
+      desktopClientDownloading: false,
+      desktopClientDownloadUrl: '',
 
       // 健康检测
       healthCheck: {
@@ -731,6 +733,70 @@ createApp({
       this._debouncedLoadUserProfile();
     },
 
+    resolveDesktopClientUrl(rawUrl) {
+      const trimmed = String(rawUrl || '').trim();
+      if (!trimmed) return '';
+      try {
+        return new URL(trimmed, `${this.apiBase}/`).toString();
+      } catch (error) {
+        console.warn('[客户端下载] 下载地址格式异常:', trimmed, error);
+        return '';
+      }
+    },
+
+    triggerDesktopClientDownload(url) {
+      const resolved = this.resolveDesktopClientUrl(url);
+      if (!resolved) return false;
+      const link = document.createElement('a');
+      link.href = resolved;
+      link.target = '_blank';
+      link.rel = 'noopener noreferrer';
+      link.download = '';
+      document.body.appendChild(link);
+      link.click();
+      link.remove();
+      return true;
+    },
+
+    async fetchDesktopClientDownloadUrl() {
+      try {
+        const response = await axios.get(`${this.apiBase}/api/client/desktop-update`, {
+          params: {
+            currentVersion: '0.0.0',
+            platform: 'windows-x64',
+            channel: 'stable'
+          }
+        });
+        const resolved = this.resolveDesktopClientUrl(response.data?.downloadUrl);
+        if (resolved) {
+          this.desktopClientDownloadUrl = resolved;
+          return resolved;
+        }
+      } catch (error) {
+        console.warn('[客户端下载] 获取最新版下载地址失败:', error?.message || error);
+      }
+      return this.resolveDesktopClientUrl(this.desktopClientDownloadUrl);
+    },
+
+    async downloadDesktopClient() {
+      if (this.desktopClientDownloading) return;
+      this.desktopClientDownloading = true;
+      try {
+        const downloadUrl = await this.fetchDesktopClientDownloadUrl();
+        if (!downloadUrl) {
+          this.showToast('warning', '暂无安装包', '服务器尚未配置客户端安装包下载地址');
+          return;
+        }
+        if (!this.triggerDesktopClientDownload(downloadUrl)) {
+          this.showToast('error', '下载失败', '下载地址无效，请稍后重试');
+          return;
+        }
+        this.showToast('success', '开始下载', '客户端安装包已开始下载');
+      } finally {
+        this.desktopClientDownloading = false;
+      }
+    },
+
     // ========== 主题管理 ==========
     // 初始化主题
     async initTheme() {