feat(materials): show save progress overlay while optimizing images

Block the editor with a spinner and percent stages during material upsert so long image optimization is visible and non-interactive.

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

app/main/index.ts

@@ -83,6 +83,16 @@ function emitScenePreviewImportProgress(evt: ScenePreviewImportEvent): void {
   }
 }
 
+function emitMaterialUpsertProgress(evt: {
+  percent: number;
+  stage: string;
+  detail?: string;
+}): void {
+  for (const win of BrowserWindow.getAllWindows()) {
+    win.webContents.send(ipcChannels.project.materialUpsertProgress, evt);
+  }
+}
+
 /**
  * Отключение GPU ломает скорость вторичных окон (презентация/пульт — WebGL). По умолчанию не трогаем.
  * При чёрном экране в упакованной сборке: `DND_DISABLE_GPU=1`.
@@ -647,11 +657,14 @@ async function main() {
       }
       filePath = filePaths[0];
     }
-    const project = await projectStore.upsertMaterial({
-      ...(materialId ? { materialId } : {}),
-      name,
-      ...(filePath ? { filePath } : {}),
-    });
+    const project = await projectStore.upsertMaterial(
+      {
+        ...(materialId ? { materialId } : {}),
+        name,
+        ...(filePath ? { filePath } : {}),
+      },
+      (p) => emitMaterialUpsertProgress(p),
+    );
     syncMaterialsOverlayWithProject(project);
     emitMaterialsOverlayState();
     emitSessionState();