Gitea repository media API stored XSS

The Gitea API endpoint `GET /api/v1/repos/{owner}/{repo}/media/{filepath}` wrote files of up to 1 KiB that are stored directly in Git, not in LFS, to the response without the content type and disposition headers Gitea uses for user content. An HTML file committed to a repository was therefore rendered by the browser on the Gitea origin. A user who can push to a repository could run JavaScript in the session of a victim who opens the media URL and act with the victim's permissions.