ci: gate import-scale and unevaluated-export anti-patterns

Static scan of snippets and templates so the two new rules fail on a
deliberate canary, not only on good input. examples/ is excluded because
pathology witnesses are intentional.

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: TMHSDigital

.github/workflows/validate.yml

@@ -130,6 +130,9 @@ jobs:
           fi
           echo "All snippets have valid Python syntax."
 
+      - name: Check import-scale and unevaluated-export anti-patterns
+        run: python3 tests/check_import_export_rules.py
+
       - name: Validate template Python syntax
         run: |
           echo "Checking template Python syntax..."

tests/check_import_export_rules.py

@@ -0,0 +1,86 @@
+"""Static checks for validate-imported-mesh-scale and
+no-unapplied-modifiers-on-export.
+
+Scans snippets/ and templates/**/*.py. examples/ is excluded because several
+examples are intentional pathology witnesses (unapplied-scale-gltf).
+"""
+import glob
+import os
+import re
+import sys
+
+ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+REQUIRED_RULES = (
+    "rules/validate-imported-mesh-scale.mdc",
+    "rules/no-unapplied-modifiers-on-export.mdc",
+)
+
+IMPORT_RE = re.compile(r"bpy\.ops\.import_scene\.(gltf|fbx)\s*\(")
+EXPORT_RE = re.compile(
+    r"bpy\.ops\.(export_scene\.gltf|export_scene\.fbx|wm\.usd_export)\s*\("
+)
+MESH_WORK_RE = re.compile(r"bmesh\.|modifiers\.new|from_pydata|foreach_set")
+UNIT_SCALE_RE = re.compile(r"unit_settings|scale_length|global_scale")
+EXPORT_EVAL_RE = re.compile(
+    r"export_apply\s*=\s*True|evaluation_mode\s*=|use_mesh_modifiers\s*=\s*True"
+)
+MODIFIER_NEW_RE = re.compile(r"modifiers\.new")
+MODIFIER_APPLY_RE = re.compile(r"modifier_apply")
+
+
+def scan_paths(extra):
+    paths = []
+    paths.extend(glob.glob(os.path.join(ROOT, "snippets", "*.py")))
+    paths.extend(
+        glob.glob(os.path.join(ROOT, "templates", "**", "*.py"), recursive=True)
+    )
+    for item in extra:
+        paths.append(item if os.path.isabs(item) else os.path.join(ROOT, item))
+    return paths
+
+
+def check_text(rel, text):
+    errors = []
+    if IMPORT_RE.search(text) and MESH_WORK_RE.search(text):
+        if "transform_apply" not in text or not UNIT_SCALE_RE.search(text):
+            errors.append(
+                f"{rel}: import_scene gltf/fbx plus mesh work without "
+                "transform_apply and a unit-scale check "
+                "(unit_settings, scale_length, or global_scale)"
+            )
+    if EXPORT_RE.search(text) and MODIFIER_NEW_RE.search(text):
+        if not EXPORT_EVAL_RE.search(text) and not MODIFIER_APPLY_RE.search(text):
+            errors.append(
+                f"{rel}: export with modifiers.new but no export_apply=True, "
+                "evaluation_mode, or modifier_apply"
+            )
+    return errors
+
+
+def main(argv):
+    errors = []
+    for rule in REQUIRED_RULES:
+        path = os.path.join(ROOT, rule)
+        if not os.path.isfile(path):
+            errors.append(f"missing rule file {rule}")
+
+    extra = argv[1:]
+    for path in scan_paths(extra):
+        if not os.path.isfile(path):
+            errors.append(f"missing scan path {path}")
+            continue
+        rel = os.path.relpath(path, ROOT).replace("\\", "/")
+        text = open(path, encoding="utf-8").read()
+        errors.extend(check_text(rel, text))
+
+    if errors:
+        for err in errors:
+            print(f"ERROR: {err}", file=sys.stderr)
+        return 1
+    print("import/export anti-pattern checks passed.")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))