feature request: download option for files

[GiFuJo]

Checklist

• [X] I checked that this feature has not been requested before
• [X] I checked that this feature is not in the "Not planned" list
• [ ] This feature will benefit the majority of users

Problem Description / Use Case

When accessing the server from another device via the web interface, the ability to download individual files could be useful for scenarios such as:

• Checking files for issues (e.g., verifying hash sums) without needing to establish an SCP/FTP/... connection.
• Moving files to external storage media without needing physical access to the server.
• Playing back files locally on your computer if streaming encounters issues.

Proposed Solution

Add a "Download file" option to the episode menu like shown below. File names should probably be sanitized in some way to avoid cross-platform issues (e.g., file name length, illegal characters).