Fix launchd domain mismatch between container system start/stop

[JaewonHur]

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Motivation and Context

getDomainString() picked gui/ or user/ based on the calling shell's launchd session type (Aqua vs Background), so registering the apiserver from a GUI Terminal and stopping it from tmux/ssh computed different domains, causing bootout to silently target a domain the service was never registered in.

Always resolve to user/ instead: it's the parent of the Aqua session domain for the same UID, so lookups from GUI shells still find it, and start/stop now agree regardless of which shell invokes them.

Testing

• Tested locally
• Added/updated tests
• Added/updated docs

[JaewonHur]

Has some issue when container system needs a GUI alert for user, like asking keychain password.

[github-actions]

Code Coverage

Tier	Line Coverage
Unit	24.35%
Integration	66.19%
Combined	75.6%

[jglogan]

@JaewonHur what issue does this fix?

[JaewonHur]

I often do container system start on normal terminal, or tmux terminal. Then, every time, the container launchd services are started under different domain (i.e., gui/501 when starting from normal terminal, user/501 when from tmux). It gets confusing when stopping container system because stopping it from different domain tricks me as if the system is stopped correctly, but not. I often wasted my time debugging leftover launchd services.