Custom domain haulx.us stuck on an inaccessible app — requesting release

Hello SWA team,

When adding the apex domain **haulx.us** to our Static Web App (default hostname: `wonderful-bush-09f56861e.7.azurestaticapps.net`, West US 2, Free tier), every attempt fails immediately with:

> (Conflict) Request Envelope is invalid. Please ensure the custom domain is not linked to another site.

This happens both from the portal and via `az staticwebapp hostname set --validation-method dns-txt-token`.

The domain was previously attached to an experimental Static Web App created under a Microsoft account we no longer have access to (the app itself appears to have been deleted, but the hostname registration seems to linger). We have enumerated every subscription in both tenants we control — no Static Web App holds this hostname.

We control the domain's DNS (Cloudflare) and can add any TXT record you need to prove ownership of **haulx.us**.

Could you please release the stale hostname registration (or advise the correct path)? Thank you!

The report names the Azure portal and `az staticwebapp hostname set --validation-method dns-txt-token` as reproduction paths; start by reproducing the conflict with the supplied hostname. Use the DNS ownership details and subscription findings to identify the service-side release or escalation path; done means the domain can be attached to the target app or the correct path is documented.

Written by the indexing model from the issue text.