GRM-53: refactor: enforce script separation and document import rules

scripts/ci/platforms.py

@@ -0,0 +1,22 @@
+"""Supported OS platform matrix for molecule tests.
+
+Single source of truth for the platform list used by both:
+- ``scripts/ci/distribute_molecule.py`` (CI parallel matrix)
+- ``scripts/molecule_all.py`` (local sequential runner)
+
+Keeping this in a dedicated module avoids cross-imports between
+dev tools and CI scripts.
+"""
+
+from __future__ import annotations
+
+#: Supported OS platform matrix.
+#: Each entry maps a short name to (image, command).
+#: The command must be systemd since rootless Docker requires
+#: loginctl/systemctl --user.
+PLATFORMS: list[dict[str, str]] = [
+    {"name": "ubuntu-2204", "image": "geerlingguy/docker-ubuntu2204-ansible:latest", "command": "/lib/systemd/systemd"},
+    {"name": "ubuntu-2404", "image": "geerlingguy/docker-ubuntu2404-ansible:latest", "command": "/lib/systemd/systemd"},
+    {"name": "debian-12", "image": "geerlingguy/docker-debian12-ansible:latest", "command": "/lib/systemd/systemd"},
+    {"name": "archlinux", "image": "marcstraube/archlinux-ansible:latest", "command": "/usr/lib/systemd/systemd"},
+]