[split] Refactor / cleanup — from #21

[pull-apart]

Automated split from #21.

Context

This is the refactor / cleanup half of an automated split from #21.

Changes in this PR:

• utilities/console.py: Added pty, shlex, subprocess, pexpect.fdpexpect imports.
• Introduced _proc attribute to Console class to store subprocess.Popen instance.
• Replaced direct pexpect.spawn calls with a new internal mechanism using pty.openpty() and subprocess.Popen.
• Added _spawn_console() method to encapsulate the new console spawning logic.
• Added _terminate_proc() method for cleanly shutting down the subprocess.
• Updated connect() to use _spawn_console() and ensure _terminate_proc() is called on connection errors.
• Updated disconnect() to check _proc status and call _terminate_proc() for cleanup.
• Simplified console_eof_sampler() to use _spawn_console() internally and remove redundant parameters (func, command, timeout).
• Changed exception handling in connect() from Exception to specific TimeoutExpiredError and pexpect.exceptions.ExceptionPexpect.

How this split maps your changes

• Refactor branch (split-pr-21-1783449463-refactor): files classified as cleanup / mechanical work:
  • utilities/console.py
• Main branch (split-pr-21-1783449463-main): files classified as feature / behavior work:
  • utilities/unittests/test_console.py

Merge order

Merge the refactor PR first if it touches shared files or would conflict with the main PR; then merge the main PR. Resolve conflicts in the usual way if both branches touch the same lines.

Main PR: #38