app-server: notify clients of remote-control status changes

[euroelessar]

Why

Remote-control app-server enrollments have both an internal server id and the environment id exposed to remote-control clients. App-server clients need one current status snapshot that says whether remote control is usable and which environment id, if any, is exposed.

A temporary websocket disconnect is not itself an identity change. Account changes, stale enrollment invalidation, successful re-enrollment, and missing ChatGPT auth are meaningful status changes. Disabled remote control remains disabled regardless of auth or SQLite state. SQLite startup failure disablement and enrollment persistence failures are handled in #20068; this PR reports the resulting effective status to clients.

What changed

• Adds v2 remoteControl/status/changed carrying state and environmentId.
• Adds RemoteControlConnectionState values: disabled, connecting, connected, and errored.
• Exposes remote-control status updates through RemoteControlHandle using a Tokio watch channel.
• Always sends the current remote-control status snapshot to newly initialized app-server clients.
• Broadcasts status changes to initialized app-server clients when state or environment id changes.
• Treats missing ChatGPT auth as an errored status while leaving it retryable because auth can change at runtime.
• Clears environmentId when enrollment is cleared for account changes, auth loss, stale backend invalidation, or disabled remote control.
• Updates app-server protocol schema fixtures, generated TypeScript, app-server README, remote-control tests, and TUI exhaustive notification matches.

Stack

• Builds on app-server: disable remote control without sqlite #20068.

Verification

• just write-app-server-schema
• cargo test -p codex-app-server-protocol
• cargo test -p codex-app-server transport::remote_control --lib
• cargo check -p codex-tui
• just fix -p codex-app-server-protocol
• just fix -p codex-app-server
• just fix -p codex-tui

[SagarJadhav30]

best intreseting

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 97b944a76b

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[owenlin0]

focused mostly on the API and skimmed the impl given that it is isolated to remote_control. codex flagged some comments though, worth addressing?