Migrate a Provider from the Legacy CLI

Port an existing grafana-cloud-cli resource client into this repository's gcx provider system — core adapter, schema/example registration, CRUD redirect commands, and ancillary subcommands.

Read this before the recipe. A human drives this skill; it is not covered by the integrate-with-gcx v1 workflow. In these instructions, "legacy CLI" means grafana-cloud-cli, whose binary was also named gcx; "gcx" means this repository's bin/gcx. Use bin/gcx for the build under review, and name the legacy binary's own path explicitly.

Of the recipe's mechanical steps, only the registration flow (providers.Register() + TypedRegistrations(), and the TypedCRUD Descriptor/Aliases fields) has been checked against current code. Treat the rest as unaudited and verify as you go.