The backend suite only ever ran on ubuntu-latest, which is why #1146 shipped:
every configured model root counted twice, the duplicate shadowed the live root
as unreachable, and models deleted from disk were never pruned again. That whole
class of bug depends on `os.sep`/`os.name`, so a Linux-only matrix cannot see it.
* New `pytest-windows` job on `windows-latest` running the same suite. No
coverage upload: the Linux job keeps producing that artifact.
* Informational for now (`continue-on-error: true`) so pre-existing Windows
failures surface in the Actions UI without blocking merges; the flag comes off
once the suite is Windows-clean.
* The symlink probe reports instead of aborting: `os.symlink` needs Developer
Mode or an elevated shell on Windows, and a runner without it should still show
the real test results.
Add a Python script step to verify that the CI environment supports directory symlinks before running tests. This ensures that symlink-dependent tests will not fail due to environment limitations.
Will Miao