Support downloading directories as a zip archive (#106)

* Add directory download as zip feature

Implements the ability for users to download directories as zip files if enabled in config. Adds a new API route for directory zipping, updates UI components to show a download button for directories, and introduces related config and type changes. Also includes a new download icon.

* Windows path bugfix

* Include empty directories in zip archive

* Address feedback

- `isDirectoryDownloadsAllowed` -> `areDirectoryDownloadsAllowed`
- send `parentPath` & `name` to API instead of resolving `fullPath` on client
- call `ensureUserPathIsValidAndSecurelyAccessible` before zipping
- set config `allowDirectoryDownloads` default to `false`
- add `zip` to Dockerfile and replace in-house zip algorithm
- replace `download.svg` with heroicon's `arrow-down-tray`
- `replace` with glob -> `replaceAll` with string

* Cleanup apt-get command

* Remove unused zip archive and directory functions

lib/models/files.ts

@@ -598,7 +598,11 @@ export async function ensureUserPathIsValidAndSecurelyAccessible(userId: string,
 
   const resolvedFullPath = `${resolve(fullPath)}/`;
 
-  if (!resolvedFullPath.startsWith(userRootPath)) {
+  // Normalize path separators for consistent comparison on Windows
+  const normalizedUserRootPath = userRootPath.replaceAll('\\', '/');
+  const normalizedResolvedFullPath = resolvedFullPath.replaceAll('\\', '/');
+
+  if (!normalizedResolvedFullPath.startsWith(normalizedUserRootPath)) {
     throw new Error('Invalid file path');
   }
 }