dmcheck: check installed package names exactly

[ranicharradi]

Summary

• Use pacman -Q "$package" for all nine installed-package checks in dmcheck.
• Avoid substring and description matches from pacman -Qs, which can enable a display manager that is not installed.

Why

pacman -Qs ly succeeds when plymouth is installed, even if ly is absent. The Ly block can then remove the tty2 getty link and create a dangling ly@tty2.service link.

Verification

• bash -n archiso/airootfs/usr/local/bin/dmcheck
• git diff --check
• Mocked pacman, rm, and ln: all nine queries used -Q, and no service actions ran when Ly was absent.

[ventureoo]

Honestly, I think we need to replace it with loop & associative array.

[vnepogodin]

What about using lua hah

[ventureoo]

What about using lua hah

When 🥹