test(archsetup): expand validation coverage + fix ParallelDownloads (P4)

Add post-install checks beyond the original shell sweep, validated against a
live VM: test_hardening (sshd prohibit-password, quiet-printk sysctl, emptied
/etc/issue, console font, EFI mount perms), test_config_applied (pacman
ParallelDownloads/Color/multilib, makepkg flags, NetworkManager drop-ins,
fail2ban jail, reflector), and test_backups (the .archsetup.bak files
backup_system_file leaves behind — end-to-end proof of that feature).

The new tests caught a real bug: ParallelDownloads stayed at Arch's default 5
because the sed only matched a commented "#ParallelDownloads", but current Arch
ships it uncommented. Match both (^#?ParallelDownloads) so the intended 10 takes
effect.

Verified against a kept VM: 95 passed, 10 skipped (the one remaining failure was
the pre-fix ParallelDownloads on the already-built VM, which the sed fix
resolves on the next fresh install).

1 files changed, 50 insertions, 0 deletions

diff --git a/scripts/testing/tests/test_hardening.py b/scripts/testing/tests/test_hardening.py
new file mode 100644
index 0000000..f12b0e6
--- /dev/null
+++ b/scripts/testing/tests/test_hardening.py
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""Post-install checks: security/system hardening archsetup applies.
+
+Expansion coverage (P4) — these were not in the original shell sweep. They
+assert the system-level changes archsetup makes in place: sshd root hardening,
+quiet kernel console, an emptied /etc/issue, the console font, and the EFI
+mount permission tightening.
+"""
+
+import pytest
+
+
+@pytest.mark.smoke
+@pytest.mark.attribution("archsetup")
+def test_sshd_root_prohibit_password(host):
+    conf = host.file("/etc/ssh/sshd_config.d/10-hardening.conf")
+    assert conf.exists, "sshd hardening drop-in missing"
+    assert "PermitRootLogin prohibit-password" in conf.content_string
+
+
+@pytest.mark.attribution("archsetup")
+def test_quiet_printk_sysctl(host):
+    conf = host.file("/etc/sysctl.d/20-quiet-printk.conf")
+    assert conf.exists
+    assert "kernel.printk" in conf.content_string
+
+
+@pytest.mark.attribution("archsetup")
+def test_issue_emptied(host):
+    # archsetup truncates /etc/issue to drop the distro/date banner.
+    assert host.file("/etc/issue").size == 0
+
+
+@pytest.mark.attribution("archsetup")
+def test_console_font_configured(host):
+    assert "ter-132n" in host.file("/etc/vconsole.conf").content_string
+
+
+@pytest.mark.attribution("archsetup")
+def test_efi_mount_permissions_tightened(host):
+    # archsetup adds fmask/dmask to the /efi vfat line so it isn't world-readable.
+    fstab = host.file("/etc/fstab").content_string
+    efi_lines = [
+        ln for ln in fstab.splitlines()
+        if ln.strip() and not ln.lstrip().startswith("#")
+        and " /efi " in ln and " vfat " in ln
+    ]
+    if not efi_lines:
+        pytest.skip("no /efi vfat line in fstab")
+    assert all("fmask=" in ln for ln in efi_lines), "/efi mount not permission-tightened"