Added sanity check baseline made by claude.

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

checks/__init__.py

@@ -0,0 +1,16 @@
+"""Check modules.
+
+Every module in this package (and its sub-packages) is imported at
+registration, so dropping a ``.py`` file containing ``Check`` subclasses
+anywhere in here is enough to add checks. Sub-packages are only used for
+grouping, the ``contexts`` attribute of each check decides where it runs.
+"""
+
+import importlib
+import pkgutil
+
+
+def load_all():
+    """Import every check module so their classes register themselves."""
+    for info in pkgutil.walk_packages(__path__, __name__ + "."):
+        importlib.import_module(info.name)