[split] Main changes — from #21

[pull-apart]

Automated split from #21.

Context

This is the main / behavior half of an automated split from #21.

Changes in this PR:

• utilities/unittests/test_console.py: Added subprocess, pexpect, pytest imports.
• Added _single_attempt_sampler helper for mocking TimeoutSampler behavior in tests.
• Updated test_console_disconnect_terminated_child to mock the new _proc attribute instead of child.terminated.
• Updated existing console_eof_sampler tests to reflect changes in its signature and internal calls.
• Added new test cases for _spawn_console covering successful execution, subprocess.Popen failure, fdspawn failure, and cleanup on error.
• Added new test cases for _terminate_proc covering termination of running processes, already terminated processes, timeout scenarios, and no process.
• Added test_connect_error_cleanup to verify proper cleanup during connection failures.
• Added test_disconnect_calls_terminate_proc to ensure process termination during disconnect.
• Modified existing tests to align with the new internal implementation, such as using shlex.split and adapting mock setups.

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.

Refactor PR: #37