Finally managed to get a user-editable interface going for https://artbybecki.com. It's hilariously barebones. Ended up using fly.io to host a tiny Go application and SQLite database (to be migrated to a postgres instance), uploading to Backblaze B2's S3-compatible API. Seems to be working quite nicely so far.
Oh, also gave it a complete facelift after discussion with the client :p