Add multilingual audit CI pipeline + extract mandelblog_content_guard

mandelblog_content_guard/mixins.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from django.core.exceptions import ValidationError
+
+
+class MultilingualValidationMixin:
+    """Opt-in mixin for project models that want explicit clean()-time enforcement."""
+
+    def clean(self):
+        from .types import format_issue
+        from .validators.multilingual import validate_snippet_instance
+
+        super_clean = getattr(super(), "clean", None)
+        if callable(super_clean):
+            super_clean()
+        issues = validate_snippet_instance(self)
+        blocking = [issue for issue in issues if issue.blocks]
+        if blocking:
+            raise ValidationError({"content_guard": [format_issue(issue) for issue in blocking]})