This removes the Nginx dependency for protecting admin pages.
BasicAuth is configured in config.toml. This is a "temporary"
setup until a full fledged auth mechanism is added.
- Add missing `app.root_url` key in migration.
- Register `/settings` handler in the backend.
- Add dummy dots in secret fields on the UI for visibility.
- On boot, the app now checks if the DB version matches its
expected version and refuses to start if there are pending
migrations to be run.
- The new `--upgrade` flag runs data migrations from the last
recorded migration (in the settings table) to the latest one
in the binary.
- Migrations are DB/arbitrary logic functions in .go files in
internal/migrations.
- All migration functions are idempotent.
Kailash Nadh