chore: checkpoint web Blender migration source, tools and docs

Accumulated uncommitted work: GHOST Web backend, WebGL/GPU web layer,
web workflow engine and protocol, tooling, docs and task records.
Large generated evidence, user-testing archives, build snapshots and
imported test assets remain untracked.

Co-Authored-By: Claude Code <noreply@anthropic.com>

blender-5.2.0/source/blender/blenkernel/intern/attribute.cc

@@ -231,6 +231,45 @@ static bool mesh_attribute_valid(const Mesh &mesh,
   return true;
 }
 
+/* UV consumers bind these roles by name, independently of the attribute's
+ * storage. Keep all roles attached to the same layer in object and edit mode. */
+static void mesh_uv_map_rename_references(Mesh &mesh,
+                                          const StringRef old_name,
+                                          const StringRef new_name)
+{
+  const bool active = old_name == mesh.active_uv_map_name();
+  const bool render = old_name == mesh.default_uv_map_name();
+  const bool stencil = old_name == StringRef(mesh.stencil_uv_map_attribute);
+  const bool clone = old_name == StringRef(mesh.clone_uv_map_attribute);
+  if (active) {
+    mesh.uv_maps_active_set(new_name);
+  }
+  if (render) {
+    mesh.uv_maps_default_set(new_name);
+  }
+  if (stencil) {
+    MEM_SAFE_DELETE(mesh.stencil_uv_map_attribute);
+    mesh.stencil_uv_map_attribute = BLI_strdupn(new_name.data(), new_name.size());
+  }
+  if (clone) {
+    MEM_SAFE_DELETE(mesh.clone_uv_map_attribute);
+    mesh.clone_uv_map_attribute = BLI_strdupn(new_name.data(), new_name.size());
+  }
+}
+
+static void mesh_uv_map_remove_references(Mesh &mesh, const StringRef name)
+{
+  if (name == StringRef(mesh.stencil_uv_map_attribute)) {
+    MEM_SAFE_DELETE(mesh.stencil_uv_map_attribute);
+  }
+  if (name == StringRef(mesh.clone_uv_map_attribute)) {
+    MEM_SAFE_DELETE(mesh.clone_uv_map_attribute);
+  }
+  /* Removal and same-name recreation can happen between draws. A name/layout
+   * comparison alone cannot observe that transition, so invalidate at mutation. */
+  BKE_mesh_batch_cache_dirty_tag(&mesh, BKE_MESH_BATCH_DIRTY_UVEDIT_ALL);
+}
+
 bool BKE_attribute_rename(AttributeOwner &owner,
                           const StringRef old_name,
                           const StringRef new_name,
@@ -291,7 +330,15 @@ bool BKE_attribute_rename(AttributeOwner &owner,
         BKE_id_attributes_default_color_set(&mesh->id, result_name);
       }
 
+      const bool is_uv_map = attr.domain == AttrDomain::Corner &&
+                             attr.type == bke::AttrType::Float2;
+      if (is_uv_map) {
+        mesh_uv_map_rename_references(*mesh, old_name, result_name);
+      }
       StringRef(result_name).copy_utf8_truncated(const_cast<CustomDataLayer *>(attr.layer)->name);
+      if (is_uv_map) {
+        BKE_mesh_batch_cache_dirty_tag(mesh, BKE_MESH_BATCH_DIRTY_UVEDIT_ALL);
+      }
 
       return true;
     }
@@ -336,11 +383,9 @@ bool BKE_attribute_rename(AttributeOwner &owner,
     if (old_name == BKE_id_attributes_default_color_name(&mesh->id)) {
       BKE_id_attributes_default_color_set(&mesh->id, new_name);
     }
-    if (old_name == mesh->active_uv_map_name()) {
-      mesh->uv_maps_active_set(new_name);
-    }
-    if (old_name == mesh->default_uv_map_name()) {
-      mesh->uv_maps_default_set(new_name);
+    if (attr->domain() == AttrDomain::Corner && attr->data_type() == bke::AttrType::Float2) {
+      mesh_uv_map_rename_references(*mesh, old_name, new_name);
+      BKE_mesh_batch_cache_dirty_tag(mesh, BKE_MESH_BATCH_DIRTY_UVEDIT_ALL);
     }
   }
 
@@ -418,6 +463,9 @@ CustomDataLayer *BKE_attribute_new(Mesh &mesh,
     return nullptr;
   }
   BM_data_layer_add_named(&bm, customdata, type, uniquename.c_str());
+  if (type == CD_PROP_FLOAT2 && domain == AttrDomain::Corner) {
+    BKE_mesh_batch_cache_dirty_tag(&mesh, BKE_MESH_BATCH_DIRTY_UVEDIT_ALL);
+  }
   const int index = CustomData_get_named_layer_index(customdata, type, uniquename);
   return (index == -1) ? nullptr : &(customdata->layers[index]);
 }
@@ -522,6 +570,7 @@ bool BKE_attribute_remove(AttributeOwner &owner, const StringRef name, ReportLis
           if (type == CD_PROP_FLOAT2 && domain == int(AttrDomain::Corner)) {
             char buffer[MAX_CUSTOMDATA_LAYER_NAME];
             BM_data_layer_free_named(em->bm, data, BKE_uv_map_pin_name_get(name_copy, buffer));
+            mesh_uv_map_remove_references(*mesh, name_copy);
           }
           return true;
         }
@@ -575,6 +624,7 @@ bool BKE_attribute_remove(AttributeOwner &owner, const StringRef name, ReportLis
     if (bke::mesh::is_uv_map(metadata)) {
       char buffer[MAX_CUSTOMDATA_LAYER_NAME];
       attributes->remove(BKE_uv_map_pin_name_get(name_copy, buffer));
+      mesh_uv_map_remove_references(*mesh, name_copy);
     }
     return true;
   }