Are you aware of pocketbase? https://pocketbase.io/ I think it could work for your usecase, even though its generally focused on being a backend. I have had a very nice experience.
PocketBase is great too. Manifest brings something different: it's fully code-based, so you can stay in your IDE, use AI tools like Copilot or Cursor to build your backend, and keep everything versioned in Git. It fits naturally into dev workflows, and we’ve got more coming soon on the AI side, both around AI and new features.