feat: add zip download for folders in file manager

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/api/index.ts

@@ -192,6 +192,7 @@ export const api = {
     tree: () => request<FileNode[]>('/files/tree'),
     getContent: (path: string) => request<{ path: string; content: string }>(`/files/content?path=${encodeURIComponent(path)}`),
     download: (path: string) => `${API_BASE_URL}/files/download?path=${encodeURIComponent(path)}`,
+    downloadZip: (path: string) => `${API_BASE_URL}/files/download-zip?path=${encodeURIComponent(path)}`,
     saveContent: (path: string, content: string) => request('/files/content', { method: 'POST', body: JSON.stringify({ path, content }) }),
     create: (path: string, isDir: boolean) => request('/files/create', { method: 'POST', body: JSON.stringify({ path, isDir }) }),
     delete: (path: string) => request('/files/delete', { method: 'POST', body: JSON.stringify({ path }) }),
@@ -725,4 +726,3 @@ export const LOG_STATUS = {
   FAILED: 'failed'
 } as const
 
-