test(archsetup): port full shell validation sweep to Testinfra (P2)

Port all ~26 post-install checks from validation.sh to pytest/Testinfra,
reaching parity before the cutover. Adds test_users, test_packages,
test_services, test_desktop, test_boot, test_keyring, and test_archsetup
(88 tests after parametrizing groups, services, timers, tools, and configs),
plus shared conftest fixtures for ZFS/NVMe/compositor/networking gating.

The shell sweep's three outcomes map cleanly: hard failures become assertions,
advisory warnings and unmet preconditions (headless compositor, slirp
networking, optional services, non-ZFS/non-NVMe hosts) become skips.

One correctness fix vs the shell sweep: check awww, not swww — archsetup
installs awww (swww's successor) and `pacman -Q swww` no longer matches.

Verified on the host: py_compile clean, pytest --collect-only green (88 tests).
The sweep against a real VM is verified by the make test run that follows.

1 files changed, 39 insertions, 0 deletions

diff --git a/scripts/testing/tests/conftest.py b/scripts/testing/tests/conftest.py
index 00632b6..c805de9 100644
--- a/scripts/testing/tests/conftest.py
+++ b/scripts/testing/tests/conftest.py
@@ -70,3 +70,42 @@ def pytest_sessionfinish(session, exitstatus):
 def target_user():
     """The account archsetup created in the VM under test."""
     return os.environ.get("ARCHSETUP_TEST_USER", "cjennings")
+
+
+@pytest.fixture(scope="session")
+def home(target_user):
+    return "/home/%s" % target_user
+
+
+@pytest.fixture(scope="session")
+def zfs_root(host):
+    """True when the VM's root filesystem is ZFS (gates ZFS-specific checks)."""
+    return host.run("findmnt -n -o FSTYPE /").stdout.strip() == "zfs"
+
+
+@pytest.fixture(scope="session")
+def has_nvme(host):
+    """True when the VM exposes an NVMe device."""
+    return host.run("ls /dev/nvme0n1 2>/dev/null").rc == 0
+
+
+@pytest.fixture(scope="session")
+def hyprland_installed(host):
+    return host.package("hyprland").is_installed
+
+
+@pytest.fixture(scope="session")
+def dwm_installed(host):
+    return host.file("/usr/local/bin/dwm").exists
+
+
+@pytest.fixture(scope="session")
+def compositor_running(host):
+    """A graphical session is live (gates socket/portal checks that need one)."""
+    return host.run("pgrep -x Hyprland").rc == 0
+
+
+@pytest.fixture(scope="session")
+def on_slirp(host):
+    """QEMU user-mode networking (10.0.2.x) — no multicast, so mDNS can't work."""
+    return "10.0.2." in host.run("ip -4 addr show").stdout