Improve codex remote-control CLI UX

[owenlin0]

Description

This PR makes codex remote-control behave like a foreground CLI command by default. Running it now starts remote control, waits for readiness, prints a clear status message with the machine name, and stays alive until Ctrl-C.

Users who want daemon behavior can use codex remote-control start, and codex remote-control stop now prints concise human-readable output. --json remains available for scripts.

Implementation-wise, this now verifies the real app-server state instead of just assuming startup worked. The CLI starts or connects to app-server, probes its control socket, calls the remoteControl/enable API, and waits for the remote-control status response/notification before printing success.

For daemon mode, codex remote-control start also reports which managed app-server binary was used, including its path and best-effort codex --version, so failures are easier to diagnose.

Examples

Example output:

> codex remote-control
Starting app-server with remote control enabled...
This machine is available for remote control as com-97826.
Press Ctrl-C to stop.

Error case using daemon (currently expected based on our publicly released CLI version):

> ./target/debug/codex remote-control start
Starting app-server daemon with remote control enabled...
Error: app server did not become ready on /Users/owen/.codex/app-server-control/app-server-control.sock

Daemon used app-server:
  path: /Users/owen/.codex/packages/standalone/current/codex
  version: 0.130.0

Managed app-server stderr (/Users/owen/.codex/app-server-daemon/app-server.stderr.log):
  error: unexpected argument '--remote-control' found
  
  Usage: codex app-server [OPTIONS] [COMMAND]
  
  For more information, try '--help'.

Caused by:
    0: failed to connect to /Users/owen/.codex/app-server-control/app-server-control.sock
    1: No such file or directory (os error 2)

What changed

• codex remote-control now runs remote control in the foreground and prints a Ctrl-C stop hint.
• codex remote-control start starts the daemon and waits for remote control readiness before reporting success.
• codex remote-control stop reports stopped/not-running status in plain language.
• Startup failures now include recent managed app-server stderr to make daemon issues easier to diagnose.
• Added coverage for CLI output, readiness waiting, foreground shutdown, and stderr log tailing.