refactor(vtk): 帘面渲染改异步走 loadSection(QPointer+generation守护,对齐volume路径)(①.3)

src/controller/VtkSceneController.cpp

@@ -103,7 +103,19 @@ void VtkSceneController::rebuildInternal() {
                     });
             }
             if (showCurtain_) {
-                for (const auto& dsId : checkedDs_) view_.addCurtain(grid(dsId), colorScale(dsId));
+                for (const auto& dsId : checkedDs_) {
+                    sceneRepo_.loadSection(
+                        dsId,
+                        [self, gen](data::SectionData s) {
+                            if (!self || gen != self->rebuildGeneration_) return;  // 已析构/迟到：丢弃
+                            self->view_.addCurtain(s.grid, s.scale);
+                            if (!self->inRebuild_) self->view_.render(false);  // 同步路径由末尾统一 render
+                        },
+                        [self, gen](const std::string& m) {
+                            if (!self || gen != self->rebuildGeneration_) return;
+                            emit self->loadFailed(QString::fromStdString(m));
+                        });
+                }
             }
             if (showVoxel_) {
                 for (const auto& dsId : checkedDs_) {