## Why
The app server's device-support probe always returned `false`, preventing the bundled TUI from advertising user verification even on supported hardware.
## What changed
Use `native::device_supported` to enable the existing initialization path for in-process `codex-tui` clients that opt into `experimentalApi`. Eligible clients advertise the `userVerification` MCP extension capability and can receive verification requests.
## Testing
Add tests covering initialization eligibility, rejection of responses from non-owning connections, ownership release before disconnected RPC handlers finish draining, and cancellation of pending requests when authentication changes.
GitOrigin-RevId: cdacc026e8f830b3340f2e6f273851c4a3031a7e
## Why
Device-authenticated verification needs an app response outside automated approval and review. Previously, MCP user-verification requests were always cancelled.
## What changed
- Add typed `openai/userVerification` elicitations carrying a title, description, and challenge through core and app-server.
- Route verification to one connection enabled by trusted host activation. Restrict responses to that owner, exclude requests from replay, and cancel on disconnect or authentication changes, including account switches away and back.
- Return proofs in `content`, discard response metadata, and cancel malformed acceptances. Suppress verification response logging and analytics, and send only a generic verification notice to realtime.
- Keep the mode experimental and exclude it from stable schema exports. Capability advertisement remains disabled, and the TUI cancels verification requests.
## Testing
Add coverage for owner isolation, disconnect and authentication races, proof response handling, automated-review bypass, inactive-host cancellation, stable schema filtering, and realtime payload exclusion. Update the MCP integration test to verify that an activated request holds the tool until the client responds.
GitOrigin-RevId: c8c7b6691a3f7756682bbcca9def1df0d1feb906