diff --git a/apps/ai-game-creator-shell/src/features/project-workspace/ResourceReferenceInput.tsx b/apps/ai-game-creator-shell/src/features/project-workspace/ResourceReferenceInput.tsx
index 2b25d8d4c..76c357582 100644
--- a/apps/ai-game-creator-shell/src/features/project-workspace/ResourceReferenceInput.tsx
+++ b/apps/ai-game-creator-shell/src/features/project-workspace/ResourceReferenceInput.tsx
@@ -53,10 +53,10 @@ import { createPortal, flushSync } from 'react-dom';
 import { PlatformResourceFilterBar } from '../../../../../packages/shared/src/components/PlatformResourceFilterBar';
 import { PlatformSegmentedTabs } from '../../../../../packages/shared/src/components/PlatformSegmentedTabs';
 import {
-  GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
   type GameCreationAppAssetManifestEntry,
   gameCreationAppAssetTags,
   type GameIterationVersion,
+  isGameCreationAppUiDesignDocAsset,
 } from '../../../../../packages/shared/src/contracts/gameCreationApp';
 import { resolveTauriInvoke } from '../../app/tauri';
 import {
@@ -1311,7 +1311,7 @@ function ResourcePickerThumbnail({
   if (mediaType.startsWith('image/')) {
     return <Loader2 size={18} className="animate-spin" aria-hidden="true" />;
   }
-  if (mediaType === GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE) {
+  if (asset && isGameCreationAppUiDesignDocAsset(asset)) {
     return <FileText size={18} aria-hidden="true" />;
   }
   return <ImageIcon size={18} aria-hidden="true" />;
diff --git a/apps/ai-game-creator-shell/src/features/ui-editor/uiDesignResourceBridge.ts b/apps/ai-game-creator-shell/src/features/ui-editor/uiDesignResourceBridge.ts
index 9d341d98f..39168801f 100644
--- a/apps/ai-game-creator-shell/src/features/ui-editor/uiDesignResourceBridge.ts
+++ b/apps/ai-game-creator-shell/src/features/ui-editor/uiDesignResourceBridge.ts
@@ -4,8 +4,7 @@ import type {
 } from '../../../../../packages/shared/src/contracts/gameCreationApp';
 import {
   GAME_CREATION_APP_UI_DESIGN_ASSET_KIND,
-  GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND,
-  GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
+  isGameCreationAppUiDesignDocAsset,
   parseGameCreationAppAssetKind,
 } from '../../../../../packages/shared/src/contracts/gameCreationApp';
 
@@ -54,11 +53,7 @@ export function findLinkedUiDesignResource(
     manifest.assets
       .filter(
         (asset) =>
-          parseGameCreationAppAssetKind(
-            asset.kind,
-            'ui-design-resource-bridge.linked-document',
-          ) === GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND &&
-          asset.mediaType === GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE &&
+          isGameCreationAppUiDesignDocAsset(asset) &&
           asset.source.referenceResourceIds?.some((reference) =>
             referenceIds.has(reference),
           ),
diff --git a/apps/ai-game-creator-shell/src/view/project-development/index.tsx b/apps/ai-game-creator-shell/src/view/project-development/index.tsx
index f8e6a334a..c89245da8 100644
--- a/apps/ai-game-creator-shell/src/view/project-development/index.tsx
+++ b/apps/ai-game-creator-shell/src/view/project-development/index.tsx
@@ -83,10 +83,10 @@ import type {
 import {
   GAME_CREATION_APP_UI_DESIGN_ASSET_KIND,
   GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND,
-  GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
 } from '../../../../../packages/shared/src/contracts/gameCreationApp';
 import {
   isGameCreationAppAssetKind,
+  isGameCreationAppUiDesignDocAsset,
   parseGameCreationAppAssetKind,
 } from '../../../../../packages/shared/src/contracts/gameCreationApp';
 import { ImageCanvasCharacterAnimationPanelView } from '../../../../../src/components/image-editor/ImageCanvasCharacterAnimationPanelView';
@@ -5262,8 +5262,7 @@ export default function ProjectDevelopmentView({
         if (canvasOpenEpochRef.current !== openEpoch) return;
         if (
           result.manifest.projectId !== manifest.projectId ||
-          result.asset.kind !== GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND ||
-          result.asset.mediaType !== GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE
+          !isGameCreationAppUiDesignDocAsset(result.asset)
         ) {
           throw new Error('UI 编辑资源结果与当前项目不一致');
         }
@@ -5400,8 +5399,7 @@ export default function ProjectDevelopmentView({
     if (uiEditorRoute) return;
     const completed = manifest.assets.find(
       (asset) =>
-        asset.kind === GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND &&
-        asset.mediaType === GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE &&
+        isGameCreationAppUiDesignDocAsset(asset) &&
         asset.source.generationKind === 'ui-workflow.completed',
     );
     if (
diff --git a/packages/shared/src/contracts/gameCreationApp.test.ts b/packages/shared/src/contracts/gameCreationApp.test.ts
index 7323aace9..d214cb871 100644
--- a/packages/shared/src/contracts/gameCreationApp.test.ts
+++ b/packages/shared/src/contracts/gameCreationApp.test.ts
@@ -16,6 +16,8 @@ import {
   GAME_CREATION_APP_COMMANDS,
   GAME_CREATION_APP_LIMITED_RUN_COMMANDS,
   GAME_CREATION_APP_MANIFEST_SCHEMA_VERSION,
+  GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND,
+  GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
   type GameCreationAgentRunTrace,
   gameCreationAppAssetCategory,
   gameCreationAppAssetCategoryForKind,
@@ -23,6 +25,7 @@ import {
   gameCreationAppAssetPersistedCategory,
   gameCreationAppAssetTags,
   type GameCreationAppManifest,
+  isGameCreationAppUiDesignDocAsset,
   normalizeGameCreationAppAssetCategory,
   normalizeGameCreationAppAssetTags,
   parseGameCreationAppAssetKind,
@@ -795,6 +798,39 @@ describe('AI 游戏创作 App 共享契约', () => {
     }
   });
 
+  it('识别 UI 编辑器文档资产只认 kind + mediaType 的唯一定义', () => {
+    expect(
+      isGameCreationAppUiDesignDocAsset({
+        kind: GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND,
+        mediaType: GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
+      }),
+    ).toBe(true);
+
+    // 只满足一半不算文档：kind 对但 mediaType 不符、mediaType 对但 kind 不是文档。
+    expect(
+      isGameCreationAppUiDesignDocAsset({
+        kind: GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND,
+        mediaType: 'text/plain',
+      }),
+    ).toBe(false);
+    expect(
+      isGameCreationAppUiDesignDocAsset({
+        kind: 'ui-design',
+        mediaType: GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
+      }),
+    ).toBe(false);
+
+    // legacy / 非 canonical kind 一律严格收口，不被当作文档（判据只做等值匹配）。
+    for (const raw of ['UI', 'ui', 'ui-design-doc ', 'UI-DESIGN-DOC']) {
+      expect(
+        isGameCreationAppUiDesignDocAsset({
+          kind: raw,
+          mediaType: GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE,
+        }),
+      ).toBe(false);
+    }
+  });
+
   it('maps every asset kind to a functional category', () => {
     expect(GAME_CREATION_APP_ASSET_CATEGORIES).toHaveLength(6);
     expect(Object.keys(GAME_CREATION_APP_ASSET_CATEGORY_BY_KIND)).toHaveLength(
diff --git a/packages/shared/src/contracts/gameCreationApp.ts b/packages/shared/src/contracts/gameCreationApp.ts
index c6c8c21f6..3981089de 100644
--- a/packages/shared/src/contracts/gameCreationApp.ts
+++ b/packages/shared/src/contracts/gameCreationApp.ts
@@ -499,6 +499,23 @@ export const GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND: GameCreationAppAssetKin
 export const GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE =
   'application/json' as const;
 
+/**
+ * 该 manifest 资产是否是 UI 编辑器文档：`kind` + `mediaType` 双条件是唯一定义。
+ *
+ * 判据原本散在三处（资源画布入口、UI 编辑器桥接、资源引用入口），任一处改了 kind /
+ * mediaType 口径就会出现「能引用但打不开」这类分叉，所以只保留这一份实现。
+ * `kind` 走严格解析：认不出的值收口成 `unknown`，不等于文档 kind。
+ */
+export function isGameCreationAppUiDesignDocAsset(
+  asset: Pick<GameCreationAppAssetManifestEntry, 'kind' | 'mediaType'>,
+): boolean {
+  return (
+    parseGameCreationAppAssetKind(asset.kind, 'ui-design-doc.asset') ===
+      GAME_CREATION_APP_UI_DESIGN_DOC_ASSET_KIND &&
+    asset.mediaType === GAME_CREATION_APP_UI_DESIGN_DOC_MEDIA_TYPE
+  );
+}
+
 /**
  * 运行期 kind 列表：穷举 Record 保证它不可能与生成 union 分叉（漏一个/多一个都编译报错）。
  * 键顺序即生成声明顺序。kind 字符串表**只有这一份运行期副本**，别名表已删除。