API key authentication

[metaathron]

Checklist

• I have filled out the template to the best of my ability.
• This only contains 1 feature request (if you have multiple feature requests, open one feature request for each feature request).
• This issue is not a duplicate feature request of previous feature requests.

Is your feature request related to a problem? Please describe.

When the Klipper/Moonraker instance has forced authentication enabled, testing the Klipper URL during setup fails with Error testing klipper url: 401, message='Unauthorized'. The integration currently has no way to authenticate against a Klipper/Moonraker instance that requires an API key, which blocks setup entirely for anyone running Moonraker with [authorization] / trusted-clients restrictions disabled or forced auth enabled.

Describe the solution you'd like

Add an optional API key field to the integration's config flow (alongside the existing Klipper URL field). When provided, the integration should send it with each request to the Klipper/Moonraker API as an X-Api-Key header (Moonraker's standard auth header), so the URL test and subsequent polling succeed against an instance with forced authentication. The field should be optional so setups without authentication continue to work unchanged.

Describe alternatives you've considered

Disabling forced authentication / trusted-clients restriction on Moonraker as a workaround — not desirable for security reasons, since it would leave the API open.

Additional context

Moonraker supports API key authentication out of the box (X-Api-Key header), so no changes on the Klipper/Moonraker side would be needed — just support for passing the key through from the integration's config.

[github-actions]

👋 Welcome to Spoolman Home Assistant Integration!

Thanks for opening your first issue! We're excited to have you here! 🎉

What happens next?

• A maintainer will review your issue soon
• Please make sure you've filled out all the required information
• Feel free to ask questions if anything is unclear!

New to contributing?

• Check out our Contributing Guide
• Look for issues labeled good first issue
• Join the discussion in other issues

We're here to help! Don't hesitate to ask questions. 💬