Added sanity check baseline made by claude.

Also changed the location to a panel in VIEW_3D instead of menu.

checks/general/structure.py

@@ -0,0 +1,50 @@
+import bpy
+
+from ... import config
+from ...core import Check, Issue, Severity, contexts, is_local
+
+
+class CollectionStructureCheck(Check):
+    """Placeholder until the production hierarchy is defined: see REQUIRED_COLLECTIONS."""
+
+    id = "collection_structure"
+    label = "Collection structure"
+    description = (
+        "No object directly in the Scene Collection, no empty collections, "
+        "and the required collections (config REQUIRED_COLLECTIONS) exist."
+    )
+    category = "Structure"
+    contexts = contexts.ASSET
+    fix_description = "Remove empty collections"
+
+    def run(self, ctx):
+        scene = ctx.scene
+        for ob in scene.collection.objects:
+            yield Issue.for_id(f"'{ob.name}' is directly in the Scene Collection", ob)
+
+        for name in config.REQUIRED_COLLECTIONS:
+            if "{asset}" in name:
+                if not ctx.asset_name:
+                    yield Issue(f"Cannot resolve required collection '{name}': unknown asset name")
+                    continue
+                name = name.format(asset=ctx.asset_name)
+            if name not in bpy.data.collections:
+                yield Issue(f"Required collection '{name}' is missing")
+
+        for collection in scene.collection.children_recursive:
+            if is_local(collection) and not collection.all_objects and not collection.children:
+                yield Issue.for_id(
+                    f"Collection '{collection.name}' is empty",
+                    collection,
+                    severity=Severity.WARNING,
+                    data={"empty": True},
+                )
+
+    def fix(self, ctx, issues):
+        for issue in issues:
+            if issue.data.get("empty"):
+                collection = issue.get_id()
+                if collection is not None:
+                    bpy.data.collections.remove(collection)
+        unfixed = [i for i in issues if not i.data.get("empty")]
+        return [f"{len(unfixed)} issue(s) must be fixed by hand"] if unfixed else []