feat(materials): free rotate session overlays and show save progress

Match NPC drag-to-rotate on the material frame during playback, and change the add/edit Save button to Saving… while import runs.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/main/materials/materialsOverlayStore.ts

@@ -18,6 +18,13 @@ function emptyState(): MaterialsOverlayState {
   };
 }
 
+function initialLayout(rotationDeg?: number): MaterialsOverlayLayout {
+  return clampMaterialsLayout({
+    ...DEFAULT_MATERIALS_OVERLAY_LAYOUT,
+    rotationDeg: rotationDeg ?? 0,
+  });
+}
+
 export class MaterialsOverlayStore {
   private state: MaterialsOverlayState = emptyState();
 
@@ -46,7 +53,7 @@ export class MaterialsOverlayStore {
         this.state = {
           revision: this.state.revision + 1,
           activeMaterialId: event.materialId,
-          layout: { ...DEFAULT_MATERIALS_OVERLAY_LAYOUT },
+          layout: initialLayout(event.rotationDeg),
           zoomTool: this.state.zoomTool,
         };
         return this.state;
@@ -57,7 +64,7 @@ export class MaterialsOverlayStore {
         this.state = {
           revision: this.state.revision + 1,
           activeMaterialId: event.materialId,
-          layout: { ...DEFAULT_MATERIALS_OVERLAY_LAYOUT },
+          layout: initialLayout(event.rotationDeg),
           zoomTool: this.state.zoomTool,
         };
         return this.state;
@@ -67,7 +74,10 @@ export class MaterialsOverlayStore {
         this.state = {
           ...this.state,
           revision: this.state.revision + 1,
-          layout: clampMaterialsLayout(event.layout),
+          layout: clampMaterialsLayout({
+            ...this.state.layout,
+            ...event.layout,
+          }),
         };
         return this.state;
       }