让状态不变量校验先判字段类型再取值

src/features/ui-editor/stateInvariants.ts 在取 path.trim 与 pixel_size.every 前先判 string / Array.isArray，残缺持久化文档此前会在 firstUiDesignInvariantMessage 里抛 TypeError，被保存流程吞成通用失败文案
tests/uiEditorState.test.ts 补三组残缺界面图都回落到 invalid-image 的用例

apps/ai-game-creator-shell/src/features/ui-editor/stateInvariants.ts

@@ -14,8 +14,12 @@ export function validateUiDesignState(state: State): UiDesignInvariantIssue[] {
   const issues: UiDesignInvariantIssue[] = [];
   const nodeIds = new Set<string>();
   for (const [id, image] of Object.entries(state.ui_design_images)) {
+    // 这个 seam 专门接住可能残缺的持久化 State，取字段前先判类型，别把 TypeError
+    // 漏给调用方，否则保存失败只会退化成通用文案。
     if (
+      typeof image.path !== 'string' ||
       image.path.trim() === '' ||
+      !Array.isArray(image.pixel_size) ||
       !image.pixel_size.every((value) => Number.isFinite(value) && value > 0) ||
       !Number.isFinite(image.pixels_per_unit) ||
       image.pixels_per_unit <= 0

apps/ai-game-creator-shell/tests/uiEditorState.test.ts

@@ -163,6 +163,22 @@ describe('useUiEditorState', () => {
     ]);
   });
 
+  it('reports malformed images instead of throwing', () => {
+    const state = structuredClone(EMPTY_UI_EDITOR_STATE);
+    for (const malformed of [
+      { pixel_size: [100, 80], pixels_per_unit: 1 },
+      { path: 'assets/page.png', pixels_per_unit: 1 },
+      { path: 'assets/page.png', pixel_size: [0, 80], pixels_per_unit: 1 },
+    ]) {
+      state.ui_design_images = {
+        page: malformed as unknown as UIDesignImage,
+      };
+      expect(validateUiDesignState(state)).toEqual([
+        expect.objectContaining({ code: 'invalid-image' }),
+      ]);
+    }
+  });
+
   it('moves a subtree between UI trees without changing its transform', () => {
     const moved = nodeWithSprite('moved');
     const initial: State = {