Added sanity check baseline made by claude.

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

checks/general/uvs.py

@@ -0,0 +1,37 @@
+import numpy as np
+
+from ... import config
+from ...core import Check, Issue, contexts
+from ...core.mesh import loop_polygon_index, polygon_arrays
+
+
+class UVCheck(Check):
+    id = "uvs"
+    label = "UVs"
+    description = "Every mesh has a UV map and no UV coordinate is negative."
+    category = "UVs"
+    contexts = contexts.ASSET
+
+    def run(self, ctx):
+        for ob in ctx.objects("MESH"):
+            me = ob.data
+            if not len(me.polygons):
+                continue
+            if not me.uv_layers:
+                yield Issue.for_id(f"{ob.name}: no UV map", ob)
+                continue
+
+            _, totals, _ = polygon_arrays(me)
+            poly_of_loop = loop_polygon_index(totals)
+            for layer in me.uv_layers:
+                uv = np.empty(len(me.loops) * 2, dtype=np.float32)
+                layer.uv.foreach_get("vector", uv)
+                negative = (uv.reshape(-1, 2) < -config.UV_NEGATIVE_TOLERANCE).any(axis=1)
+                if negative.any():
+                    faces = np.unique(poly_of_loop[negative])
+                    yield Issue.for_id(
+                        f"{ob.name}: UV map '{layer.name}' has negative UVs on {faces.size} face(s)",
+                        ob,
+                        elements=faces.tolist(),
+                        element_type="FACE",
+                    )