文生 / 图生 3D 面板入口合并到同一个 opener

- src/components/image-editor/useImageCanvasGenerationWorkflow.ts：新增 openModel3dGenerationDialog(mode)，openModel3dTextToModelDialog / openModel3dImageToModelDialog 退化成两个只传 mode 的薄包装；两条入口此前是除 mode 外逐字相同的复制，改逻辑时容易只改一处

验证：npm run typecheck

src/components/image-editor/useImageCanvasGenerationWorkflow.ts

@@ -1746,37 +1746,30 @@ export function useImageCanvasGenerationWorkflow({
     viewport,
   ]);
 
-  const openModel3dTextToModelDialog = useCallback(() => {
-    openPlacedCanvasGenerationDialog(
-      createModel3dGenerationDialogDraft({
-        canvasSize,
-        viewport,
-        mode: 'model3d-text-to-model',
-      }),
-    );
-    activateCanvasGenerationEntry('model3d');
-  }, [
-    activateCanvasGenerationEntry,
-    canvasSize,
-    openPlacedCanvasGenerationDialog,
-    viewport,
-  ]);
+  const openModel3dGenerationDialog = useCallback(
+    (mode: 'model3d-text-to-model' | 'model3d-image-to-model') => {
+      openPlacedCanvasGenerationDialog(
+        createModel3dGenerationDialogDraft({ canvasSize, viewport, mode }),
+      );
+      activateCanvasGenerationEntry('model3d');
+    },
+    [
+      activateCanvasGenerationEntry,
+      canvasSize,
+      openPlacedCanvasGenerationDialog,
+      viewport,
+    ],
+  );
 
-  const openModel3dImageToModelDialog = useCallback(() => {
-    openPlacedCanvasGenerationDialog(
-      createModel3dGenerationDialogDraft({
-        canvasSize,
-        viewport,
-        mode: 'model3d-image-to-model',
-      }),
-    );
-    activateCanvasGenerationEntry('model3d');
-  }, [
-    activateCanvasGenerationEntry,
-    canvasSize,
-    openPlacedCanvasGenerationDialog,
-    viewport,
-  ]);
+  const openModel3dTextToModelDialog = useCallback(
+    () => openModel3dGenerationDialog('model3d-text-to-model'),
+    [openModel3dGenerationDialog],
+  );
+
+  const openModel3dImageToModelDialog = useCallback(
+    () => openModel3dGenerationDialog('model3d-image-to-model'),
+    [openModel3dGenerationDialog],
+  );
 
   const openEditDialog = useCallback(
     (sourceLayer: CanvasLayer) => {