完善素材分离恢复与步骤映射

回填部分失败时重新读取恢复状态；移除冗余类型断言并改用显式步骤映射。

apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts

@@ -413,12 +413,11 @@ export function useUiEditorSession(
     resourceId !== undefined &&
     savedStateSignature !== null &&
     savedStateSignature !== stateSignature;
-  const nextStep: UiEditorStepId | null =
-    activeStep === 'reference-analysis'
-      ? 'structure-recognition'
-      : activeStep === 'structure-recognition'
-        ? 'asset-separation'
-        : null;
+  const nextStepByStep: Partial<Record<UiEditorStepId, UiEditorStepId>> = {
+    'reference-analysis': 'structure-recognition',
+    'structure-recognition': 'asset-separation',
+  };
+  const nextStep = nextStepByStep[activeStep] ?? null;
 
   const spriteReferenceCounts = useMemo(() => {
     const counts: Record<string, number> = {};
@@ -1195,13 +1194,18 @@ export function useUiEditorSession(
       }));
       if (separationResult === null)
         throw new Error('自动切分素材没有返回结果');
-      const completedResult = separationResult as SeparationDTO;
+      const completedResult = separationResult;
       if (!(await save({ allowDuringSeparation: true }))) {
         throw new Error(
           '自动切分素材结果已写入编辑器，但 State 保存失败；sidecar 已保留，可继续恢复。',
         );
       }
       if (backfillErrors.length > 0) {
+        const recovery = await invoke<SeparationRecoveryDTO>(
+          'inspect_separation_recovery',
+          { projectPath, assetId: resourceId },
+        );
+        setSeparationRecovery(recovery);
         reportWorkflowCompletion(
           'asset-separation',
           'failure',