Add get_profile tool (conforming with OpenAI ChatGPT Plugins standard)

[irvinebroque]

Add authenticated, read-only get_profile discovery so clients recognize the same Cloudflare user or account across reconnects, token refresh, scope upgrades, and display changes.

Follow OpenAI's profile-tool guidance: publish the profile marker, strict empty input and profile output schemas, read-only annotations, and explicit OAuth identity scopes through the SDK-supported _meta.securitySchemes compatibility field.

[mattzcarey]

Thanks Brendan, this was a great push to follow OpenAI's profile-tool spec. I've redone it in #258 with a few changes:

• Renamed to whoami. The API already has /accounts/{id}/profile, /user/billing/profile and /organizations/{id}/profile, so get_profile reads like one of the endpoint tools. ChatGPT finds the tool through _meta['openai/profile'], so the name doesn't matter to it.
• The ID is the Cloudflare ID with a user: or account: prefix, not a hash. OpenAI recommends using an existing immutable provider ID.
• Dropped the blanket Cache-Control: no-store. Caches don't store POST responses, and it would conflict with feat(mcp): let clients cache tools/list for an hour and share it across users #245.

Closing in favour of #258.

[irvinebroque]

Awesome