[SandObserver]

Summary

• Add an unraid provider to Disk Health that posts an array { parities disks caches } query to the Unraid GraphQL API with the x-api-key header.
• Offer every assigned parity, data and cache slot in the bay picker by slot name, skipping DISK_NP slots.
• Map DISK_OK and DISK_NEW to healthy, DISK_INVALID, DISK_WRONG, DISK_DSBL and DISK_DSBL_NEW to failed, and any other state to no status.
• Report a configured bay that is absent from the reply as failed, since Unraid omits slots without a device and a missing drive never arrives with its own state.
• Report size in bytes from the KiB slot size and no temperature for a spun-down drive.
• Add unraidUrl, unraidApiKey (secret) and unraidHref fields with translations in all six locales, and list Unraid in the README.

Testing
All green. Added 16 tests for the Unraid picker, request, state mapping, missing drive, size and temperature, refused key and link.

Changelog

Added

• Add Unraid as a Disk Health source.

Checklist

• Stays within the project constraints: one container, no runtime dependencies, no build step (see CONTRIBUTING.md).
• Tests added or updated for new logic, and the full suite, lint, and typechecks pass.
• Docs updated if behavior or configuration changed.