Match3D & Puzzle: runtime UI, assets, drag fix

Backend: stop treating background music as a required draft asset and remove auto-submit/plan for background music; load persisted generated UI/assets into Match3D agent session responses (added helpers to resolve profile id and fetch existing generated assets). Frontend: make Match3D result preview reuse runtime UI styles, unify runtime settings entry, update PuzzleRuntime to apply immediate pointermove transforms (disable drag transition), use SVG clipPath for merged piece rounding, ensure PuzzleRuntimeShell supplies platform theme classes, and adjust related tests. Docs & logs: update decision log, pitfalls and product docs to reflect these changes.

src/components/custom-world-home/CustomWorldCreationHub.interaction.test.tsx

@@ -633,7 +633,7 @@ test('creation hub published work delete action is revealed without opening card
   );
 
   expect(screen.queryByRole('button', { name: '删除' })).toBeNull();
-  expect(screen.queryByRole('button', { name: '分享' })).toBeNull();
+  expect(screen.getByRole('button', { name: '分享' })).toBeTruthy();
 
   screen.getByRole('button', { name: /查看详情《待删拼图》/u }).focus();
   await user.keyboard('{ArrowLeft}');
@@ -684,7 +684,7 @@ test('creation hub opens persisted rpg drafts by card click', async () => {
   expect(openedItems).toEqual([persistedDraft]);
 });
 
-test('creation hub published swipe share button copies share text without opening the card', async () => {
+test('creation hub published share icon copies share text without opening the card', async () => {
   const user = userEvent.setup();
   const writeText = vi.fn(async () => undefined);
   const onOpenPuzzleDetail = vi.fn();
@@ -727,9 +727,11 @@ test('creation hub published swipe share button copies share text without openin
     />,
   );
 
-  screen.getByRole('button', { name: /查看详情《沉钟拼图》/u }).focus();
-  await user.keyboard('{ArrowLeft}');
-  await user.click(screen.getByRole('button', { name: '分享' }));
+  const shareButton = screen.getByRole('button', { name: '分享' });
+  expect(shareButton).toBeTruthy();
+  expect(screen.queryByText('删除')).toBeNull();
+
+  await user.click(shareButton);
 
   expect(writeText).toHaveBeenCalledWith(
     expect.stringContaining('邀请你来玩《沉钟拼图》'),
@@ -746,6 +748,45 @@ test('creation hub published swipe share button copies share text without openin
   ).toBeTruthy();
 });
 
+test('creation hub published share icon is shown directly on the card header', () => {
+  render(
+    <CustomWorldCreationHub
+      items={[]}
+      puzzleItems={[
+        {
+          workId: 'puzzle:work-share-icon',
+          profileId: 'puzzle-profile-share-icon',
+          ownerUserId: 'user-1',
+          authorDisplayName: '拼图作者',
+          levelName: '沉钟拼图',
+          summary: '分享入口应直接露出在卡片右上角。',
+          themeTags: ['潮雾'],
+          coverImageSrc: null,
+          publicationStatus: 'published',
+          updatedAt: new Date('2026-04-22T12:00:00.000Z').toISOString(),
+          publishedAt: new Date('2026-04-22T12:10:00.000Z').toISOString(),
+          playCount: 8,
+          remixCount: 2,
+          likeCount: 0,
+          publishReady: true,
+        },
+      ]}
+      loading={false}
+      error={null}
+      onRetry={() => {}}
+      onCreateType={noopCreateType}
+      onOpenDraft={() => {}}
+      onEnterPublished={() => {}}
+      onOpenPuzzleDetail={() => {}}
+      entryConfig={testEntryConfig}
+      creationTypes={testCreationTypes}
+    />,
+  );
+
+  expect(screen.getByRole('button', { name: '分享' })).toBeTruthy();
+  expect(screen.queryByRole('button', { name: '删除' })).toBeNull();
+});
+
 test('creation hub left swipe draft reveals delete without opening card', () => {
   const onDeletePublished = vi.fn();
   const onOpenDraft = vi.fn();