feat: Remote permission server

[hegasz]

What

This PR introduces a remote permission mode to Codex CLI, enabling the agent to request command approval decisions from a remote permission server.

Why

I needed this for a project I'm working on; this is the minimal set of features I needed for my use-case but happy to polish and extend if this is something people want. Remote permission opens the door for quite a lot of downstream applications. For example, as these things get increasingly capable and people start wanting to run many in parallel, something like this is needed to avoid ending up stuck staring at dozens of tmux panels.

How

• Added new CLI flags: --remote-permission, --permission-server-url, and --agent-id to configure the remote permission workflow.
• Implemented a socket.io-based websocket client (requestRemotePermission) to connect to the server.
• Added runRemoteMode to cli.tsx - similar to existing runQuietMode.

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[hegasz]

I have read the CLA Document and I hereby sign the CLA

[codex-maintainers]

Thanks for the contribution! We're primarily focused on the native/Rust implementation of Codex CLI and would love to see if this feature is still relevant on the latest version. If it is, we're happy to take a look at a PR to the codex-rs/ implementation.