0.37.0: download whole folders (recursive) as a .zip from the file browser

The file browser/editor could only download individual files. Add a
recursive directory download that streams the folder as a zip archive,
on the local host and on every remote agent.

- file_service.archive_dir(): zip a directory recursively into a temp
  file, preserving the folder name as the archive root and empty
  subdirectories; symlinks are skipped (no sandbox escape / loops).
- /api/files/download and /agent/files/download branch on directories
  and return application/zip, cleaning up the temp file afterwards.
- Files page: show the download button for folders too (as <name>.zip).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/agent_app.py

@@ -33,6 +33,7 @@ from fastapi import (
     WebSocketDisconnect,
 )
 from fastapi.responses import FileResponse, JSONResponse
+from starlette.background import BackgroundTask
 from pydantic import BaseModel
 
 from config import settings
@@ -666,6 +667,12 @@ def files_read(path: str = Query(...)) -> dict:
 
 @app.get("/agent/files/download", dependencies=[Depends(verify_token)])
 def files_download(path: str = Query(...)):
+    if _file_guard(file_service.is_dir, path):
+        tmp, filename = _file_guard(file_service.archive_dir, path)
+        return FileResponse(
+            tmp, filename=filename, media_type="application/zip",
+            background=BackgroundTask(os.unlink, tmp),
+        )
     real, filename = _file_guard(file_service.resolve_download, path)
     return FileResponse(real, filename=filename, media_type="application/octet-stream")
 

backend/routers/files.py

@@ -20,6 +20,7 @@ from fastapi import (
     UploadFile,
 )
 from fastapi.responses import FileResponse
+from starlette.background import BackgroundTask
 from pydantic import BaseModel
 from sqlmodel import Session
 
@@ -69,6 +70,12 @@ def download(
     path: str = Query(...),
     _user: User = Depends(get_current_user),
 ):
+    if _guard(file_service.is_dir, path):
+        tmp, filename = _guard(file_service.archive_dir, path)
+        return FileResponse(
+            tmp, filename=filename, media_type="application/zip",
+            background=BackgroundTask(os.unlink, tmp),
+        )
     real, filename = _guard(file_service.resolve_download, path)
     return FileResponse(real, filename=filename, media_type="application/octet-stream")
 

backend/services/file_service.py

@@ -10,6 +10,8 @@ from __future__ import annotations
 
 import os
 import shutil
+import tempfile
+import zipfile
 
 from services.device_service import BrowseError, _is_allowed, _real_root
 
@@ -175,6 +177,47 @@ def resolve_download(path: str) -> tuple[str, str]:
     return real, os.path.basename(path)
 
 
+def is_dir(path: str) -> bool:
+    """Whether ``path`` points at a directory inside the sandbox."""
+    return os.path.isdir(_safe_real(path))
+
+
+def archive_dir(path: str) -> tuple[str, str]:
+    """Zip a directory (recursively) into a temp file.
+
+    Returns ``(tmp_zip_path, download_filename)``. The caller is responsible
+    for deleting the temp file once it has been streamed to the client.
+    Symlinks are skipped so the archive cannot escape the sandbox or loop.
+    """
+    real = _safe_real(path)
+    if not os.path.isdir(real):
+        raise BrowseError(f"Not a directory: {path}")
+    name = os.path.basename(path.rstrip("/")) or "root"
+
+    fd, tmp = tempfile.mkstemp(suffix=".zip")
+    os.close(fd)
+    try:
+        with zipfile.ZipFile(tmp, "w", zipfile.ZIP_DEFLATED) as zf:
+            for root, dirs, files in os.walk(real):
+                # Don't follow symlinked directories (avoids loops / escapes).
+                dirs[:] = [d for d in dirs if not os.path.islink(os.path.join(root, d))]
+                rel_root = os.path.relpath(root, real)
+                if not files and not dirs and rel_root != ".":
+                    # Preserve otherwise-empty directories.
+                    zf.writestr(os.path.join(name, rel_root) + "/", "")
+                for f in files:
+                    full = os.path.join(root, f)
+                    if os.path.islink(full):
+                        continue
+                    zf.write(full, os.path.join(name, rel_root, f) if rel_root != "."
+                             else os.path.join(name, f))
+    except OSError:
+        if os.path.exists(tmp):
+            os.unlink(tmp)
+        raise
+    return tmp, f"{name}.zip"
+
+
 def upload_target(
     dir_path: str,
     filename: str,

backend/version.py

@@ -1,3 +1,3 @@
 """Single source of truth for the StackPilot release version."""
 
-APP_VERSION = "0.36.1"
+APP_VERSION = "0.37.0"

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "stackpilot-frontend",
   "private": true,
-  "version": "0.36.1",
+  "version": "0.37.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/pages/Files.tsx

@@ -202,7 +202,7 @@ export function Files() {
 
   const download = (e: HostPathEntry) =>
     filesApi
-      .download(join(path, e.name), e.name, host)
+      .download(join(path, e.name), e.type === "dir" ? `${e.name}.zip` : e.name, host)
       .catch((err) => toast.error(apiErrorMessage(err)));
 
   return (
@@ -407,15 +407,13 @@ export function Files() {
                     </td>
                     <td className="px-4 py-2">
                       <div className="flex items-center justify-end gap-1">
-                        {e.type === "file" && (
-                          <button
-                            title="Download"
-                            onClick={() => download(e)}
-                            className="rounded p-1.5 hover:bg-slate-100 dark:hover:bg-slate-700"
-                          >
-                            <Download className="h-4 w-4 text-slate-500" />
-                          </button>
-                        )}
+                        <button
+                          title={e.type === "dir" ? "Download as .zip" : "Download"}
+                          onClick={() => download(e)}
+                          className="rounded p-1.5 hover:bg-slate-100 dark:hover:bg-slate-700"
+                        >
+                          <Download className="h-4 w-4 text-slate-500" />
+                        </button>
                         {isAdmin && (
                           <>
                             <button