## Why
Configured MCP servers must not be able to request user verification, even when they reuse the hosted apps server name. Local verification identity selection also needs to distinguish a user's workspace memberships.
## What changed
- Advertise `userVerification` only to the host-owned apps MCP server and cancel verification requests from other servers before prompting the client.
- Add `CodexAuth::get_chatgpt_account_user_id()` to read the access token's opaque `chatgpt_account_user_id` only when its workspace matches the selected account. Missing or malformed claims return no identity, without falling back to another user ID or breaking ordinary authentication.
## Testing
Add coverage for capability filtering, rejection of configured servers including those using the hosted apps name, and account-user identity selection with malformed or mismatched claims. Add an MCP round-trip test showing that verification waits for a client response even in full access mode, returns the supplied proof, and discards response metadata.
GitOrigin-RevId: 156e83d5a0302c013b85e564b46b4bfe858cbdb0
f326857cf4