共创页签改为只列支持共创的作品（复用广场卡片+forkable=1+加载更多），主题列表页保留但撤下页签入口

src/components/platform-entry/PlatformEntryActiveFlowShell.tsx

@@ -606,9 +606,12 @@ export function PlatformEntryFlowShellImpl({
     setSelectionStage('games', { path: '/games' });
   }, [setSelectionStage]);
 
-  /** 共创主题列表（`/games` 的「共创」页签）。 */
-  const openGameThemes = useCallback(() => {
-    setSelectionStage('game-themes', { path: '/games/themes' });
+  /**
+   * 「共创」页签：**只列支持共创的作品**（游戏卡片 + 同一套游标分页）。
+   * 它不再指向共创主题列表——主题列表页（stage `game-themes`）与路由保留，只是没有页签入口。
+   */
+  const openGameCoCreation = useCallback(() => {
+    setSelectionStage('game-co-creation', { path: '/games/co-creation' });
   }, [setSelectionStage]);
 
   const backFromGameThemes = useCallback(() => {
@@ -634,8 +637,8 @@ export function PlatformEntryFlowShellImpl({
       window.history.back();
       return;
     }
-    replaceAppHistoryPath('/games/themes');
-    setSelectionStage('game-themes', { path: '/games/themes' });
+    replaceAppHistoryPath('/games/co-creation');
+    setSelectionStage('game-co-creation', { path: '/games/co-creation' });
   }, [setSelectionStage]);
 
   /**
@@ -774,6 +777,7 @@ export function PlatformEntryFlowShellImpl({
     selectionStage === 'game-detail' ||
     selectionStage === 'game-compare' ||
     selectionStage === 'game-themes' ||
+    selectionStage === 'game-co-creation' ||
     selectionStage === 'game-theme' ||
     selectionStage === 'game-play' ||
     selectionStage === 'game-mine' ||
@@ -1049,7 +1053,7 @@ export function PlatformEntryFlowShellImpl({
                         searchKeyword={activeSearchKeyword}
                         onOpenDetail={openGameDetail}
                         onOpenMyGames={openMyGames}
-                        onOpenThemes={openGameThemes}
+                        onOpenThemes={openGameCoCreation}
                         onOpenPublish={
                           gamePublishGateAllowed ? openGamePublish : undefined
                         }
@@ -1103,6 +1107,13 @@ export function PlatformEntryFlowShellImpl({
                         onBack={backFromGameCompare}
                         onOpenDetail={openGameDetail}
                       />
+                    ) : selectionStage === 'game-co-creation' ? (
+                      <GameGalleryPage
+                        searchKeyword={activeSearchKeyword}
+                        scope="forkable"
+                        onOpenDetail={openGameDetail}
+                        onOpenGallery={openGames}
+                      />
                     ) : selectionStage === 'game-themes' ? (
                       <GameThemesPage
                         onBack={backFromGameThemes}