chore: import upstream snapshot with attribution

tests/test_skill_version_warning.py

@@ -0,0 +1,60 @@
+"""Direction-aware skill-version mismatch warning (#1568).
+
+`_check_skill_version` used to advise `graphify install` on ANY version
+mismatch. But `install` writes the package's OWN bundled skill and re-stamps
+the version, so when the skill on disk is NEWER than the package, following
+that advice silently DOWNGRADES the skill. These tests pin that the warning is
+now direction-aware: skill-older -> recommend install; skill-newer -> recommend
+upgrading the package instead.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+import graphify.__main__ as mainmod
+
+
+def _make_skill(tmp_path: Path, stamped: str) -> Path:
+    skill_dst = tmp_path / "skills" / "graphify" / "SKILL.md"
+    skill_dst.parent.mkdir(parents=True, exist_ok=True)
+    skill_dst.write_text("# graphify skill\n", encoding="utf-8")
+    (skill_dst.parent / ".graphify_version").write_text(stamped, encoding="utf-8")
+    return skill_dst
+
+
+def test_version_tuple_orders_numerically():
+    vt = mainmod._version_tuple
+    assert vt("0.9.2") > vt("0.8.27")     # 9 > 8, not string-compared
+    assert vt("0.10.0") > vt("0.9.0")     # 10 > 9
+    assert vt("0.9.3") == vt("0.9.3")
+    assert vt("1.0.0rc1") == vt("1.0.0")  # pre-release suffix compares by core
+    assert vt("") == (0,)                 # malformed stamp degrades, no raise
+
+
+def test_skill_older_than_package_recommends_install(tmp_path, monkeypatch, capsys):
+    monkeypatch.setattr(mainmod, "__version__", "0.9.3")
+    skill_dst = _make_skill(tmp_path, "0.8.27")
+    mainmod._check_skill_version(skill_dst)
+    err = capsys.readouterr().err
+    assert "Run 'graphify install' to update" in err
+    assert "downgrade" not in err
+
+
+def test_skill_newer_than_package_recommends_upgrade_not_install(tmp_path, monkeypatch, capsys):
+    monkeypatch.setattr(mainmod, "__version__", "0.8.27")
+    skill_dst = _make_skill(tmp_path, "0.9.2")
+    mainmod._check_skill_version(skill_dst)
+    err = capsys.readouterr().err
+    # must NOT tell the user to run install (that would downgrade the skill)
+    assert "Run 'graphify install' to update" not in err
+    assert "downgrade" in err
+    assert "upgrade" in err.lower()
+
+
+def test_matching_version_is_silent(tmp_path, monkeypatch, capsys):
+    monkeypatch.setattr(mainmod, "__version__", "0.9.3")
+    skill_dst = _make_skill(tmp_path, "0.9.3")
+    mainmod._check_skill_version(skill_dst)
+    assert capsys.readouterr().err == ""