[Bug]: Valid login returns 'Your account could not be migrated automatically' instead of authenticating

[kasperschnack]

What did you expect to happen?

A valid Atuin username/password should authenticate successfully, and then atuin login on a new machine should proceed normally with the account key.

What happened?

This account appears to be in a broken migration state on the hosted Atuin service.

I can distinguish three cases consistently:

1. If I enter an incorrect username or password, I get:
   Invalid credentials

2. If I enter the correct username and password, I get:
   Your account could not be migrated automatically. Please register a new account or contact support.

3. On a new machine using the same account key from a machine that is already logged in, atuin login fails and never reaches a usable authenticated state.

This strongly suggests the credentials are valid, but the remote account is in a server-side migration state that prevents login.

Steps to reproduce

1. Have an existing Atuin cloud account created before the current migration path.
2. Attempt to log in with the correct username and password.
3. Observe that correct credentials return:
   Your account could not be migrated automatically. Please register a new account or contact support.
4. Enter an incorrect username or password.
5. Observe that incorrect credentials return:
   Invalid credentials

Additional context

I also verified locally that:

• the Atuin key in my automation matches the output of atuin key from a machine that is already logged in
• the username used in automation matches the working machine
• the failure mode changes depending on whether the username/password are correct, which is what led me to conclude this is not just a bad-credentials issue

I initially hit this while bootstrapping a new machine via Ansible, but at this point it does not look like an Ansible bug. The automation is just surfacing the server-side migration failure.

Versions

• Atuin CLI on affected target: 18.15.2
• Atuin CLI on existing logged-in machine: 18.8.0

Hosted or self-hosted?

Hosted Atuin cloud / default sync server.