资源画布首屏加载增加转圈提示

进入资源画布到首屏预览落地之间画布是空的，新增居中加载态：Loader2 转圈加文案，role=status 可被读屏播报
加载判定抽到 resourceBookIsLoading：有资源且布局未就绪或首屏预览一张都没落地时显示；预览失败同样视为落地，避免一直转圈
补充 resourceBookModel 加载态用例

apps/ai-game-creator-shell/src/styles.css

@@ -5634,6 +5634,21 @@ iframe.preview-frame {
   pointer-events: none;
 }
 
+.game-resource-book-loading {
+  position: absolute;
+  inset: 0;
+  z-index: 40;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  background: rgb(255 253 250 / 78%);
+  color: #a08073;
+  font-size: 13px;
+  pointer-events: none;
+}
+
 .game-resource-book-manager[data-book-motion='running']
   .game-resource-book-scene-world {
   opacity: 0;

apps/ai-game-creator-shell/src/view/project-development/index.tsx

@@ -10,6 +10,7 @@ import {
   Image,
   Info,
   ListFilter,
+  Loader2,
   Maximize2,
   Minus,
   Music2,
@@ -98,6 +99,7 @@ import {
 } from './resourceBookLayout';
 import {
   initialResourceBookState,
+  resourceBookIsLoading,
   resourceBookReducer,
   resourceBookSceneCategory,
   resourceBookShowsChildCards,
@@ -2189,6 +2191,36 @@ export default function ProjectDevelopmentView({
     sortMode,
     visibleCategoryOrder,
   ]);
+  const resourceBookOverviewReady = useMemo(
+    () =>
+      visibleCategoryOrder.every((category) => {
+        const rect = resourceBookOverviewRects.get(category);
+        return Boolean(rect && rect.width > 0 && rect.height > 0);
+      }),
+    [resourceBookOverviewRects, visibleCategoryOrder],
+  );
+  const resourceBookSettledPreviewCount = useMemo(() => {
+    let settled = 0;
+    for (const resource of visibleResources) {
+      const identity = resourceCardPreviews.identityByResourceId.get(
+        resource.id,
+      );
+      if (!identity) continue;
+      const status = resourceCardPreviews.previews.get(identity)?.status;
+      if (status === 'loaded' || status === 'failed') settled += 1;
+    }
+    return settled;
+  }, [
+    resourceCardPreviews.identityByResourceId,
+    resourceCardPreviews.previews,
+    visibleResources,
+  ]);
+  const resourceBookLoading = resourceBookIsLoading({
+    resourceCount: visibleResources.length,
+    overviewReady: resourceBookOverviewReady,
+    cardsReady: sortMode !== 'dependency' || resourceGraphInitializationReady,
+    settledPreviewCount: resourceBookSettledPreviewCount,
+  });
   const setResourceCanvasViewport = useCallback(
     (
       category: ResourceCategory,
@@ -5590,6 +5622,20 @@ export default function ProjectDevelopmentView({
                   onWheel={handleResourceBookWheel}
                 />
                 <ResourceBookTransitionLayer />
+                {resourceBookLoading ? (
+                  <div
+                    className="game-resource-book-loading"
+                    role="status"
+                    aria-live="polite"
+                  >
+                    <Loader2
+                      size={22}
+                      aria-hidden="true"
+                      className="animate-spin"
+                    />
+                    <span>正在加载资源画布…</span>
+                  </div>
+                ) : null}
                 <div className="game-resource-book-zoom">
                   <button
                     type="button"

apps/ai-game-creator-shell/src/view/project-development/resourceBookModel.ts

@@ -78,3 +78,24 @@ export function resourceBookShowsOverviewCards(state: ResourceBookState) {
 export function resourceBookShowsChildCards(state: ResourceBookState) {
   return state.view === 'child';
 }
+
+/**
+ * 进入资源画布时，卡片布局与首屏预览都要等一会儿，这段时间画布是空的。
+ * 只要还有资源、但布局未就绪或首屏预览一个都没落地，就显示加载态。
+ * 预览失败也算落地，避免一直转圈。
+ */
+export function resourceBookIsLoading({
+  resourceCount,
+  overviewReady,
+  cardsReady,
+  settledPreviewCount,
+}: {
+  resourceCount: number;
+  overviewReady: boolean;
+  cardsReady: boolean;
+  settledPreviewCount: number;
+}) {
+  if (resourceCount <= 0) return false;
+  if (!cardsReady || !overviewReady) return true;
+  return settledPreviewCount <= 0;
+}

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

@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest';
 
 import {
   initialResourceBookState,
+  resourceBookIsLoading,
   resourceBookReducer,
   resourceBookSceneCategory,
   resourceBookShowsOverviewCards,
@@ -103,3 +104,30 @@ describe('resource book state machine', () => {
     ).toEqual(switched);
   });
 });
+
+describe('resource book loading state', () => {
+  const ready = {
+    resourceCount: 3,
+    overviewReady: true,
+    cardsReady: true,
+    settledPreviewCount: 1,
+  };
+
+  it('never blocks an empty project', () => {
+    expect(resourceBookIsLoading({ ...ready, resourceCount: 0 })).toBe(false);
+  });
+
+  it('loads while the layout or first preview is still pending', () => {
+    expect(resourceBookIsLoading({ ...ready, cardsReady: false })).toBe(true);
+    expect(resourceBookIsLoading({ ...ready, overviewReady: false })).toBe(
+      true,
+    );
+    expect(resourceBookIsLoading({ ...ready, settledPreviewCount: 0 })).toBe(
+      true,
+    );
+  });
+
+  it('stops once a first preview settles', () => {
+    expect(resourceBookIsLoading(ready)).toBe(false);
+  });
+});