Update Match3D/image-generation docs & code

Adds/updates documentation, assets and implementation for Match3D and puzzle image generation workflows. Key changes: decision logs and pitfalls updated to prefer VectorEngine Gemini for Match3D material sheets and to require edits (multipart) for 1:1 container reference images; guidance added for when to use APIMart vs VectorEngine. .env.example clarified APIMart/Responses config. Many new public assets and PPT visuals added. Code changes across frontend and backend: updated shared contracts, server-rs match3d/puzzle/image-generation handlers, VectorEngine/OpenAI image generation clients, and multiple React components/tests to handle UI/background/container image signing, edits workflow, and puzzle UI background resolution. Added src/services/puzzle-runtime/puzzleUiBackgroundSource.ts and related test updates. Includes notes about multipart HTTP/1.1 requirement and test/verification commands in docs.

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

@@ -27,9 +27,8 @@ import {
   CustomWorldWorkTabs,
 } from './CustomWorldWorkTabs';
 
-// 中文注释：草稿在手机端保持双列，已发布卡片由卡片自身跨两列展示公开指标。
 const WORK_GRID_CLASS =
-  'grid grid-cols-2 gap-2.5 sm:gap-3 md:grid-cols-2 xl:grid-cols-3 2xl:grid-cols-4';
+  'creation-work-list grid min-w-0 gap-3 sm:gap-3.5 xl:gap-4';
 const WORK_METRIC_CACHE_KEY = 'genarrative.creationHub.publishedMetrics.v1';
 
 type WorkMetricSnapshot = Record<
@@ -268,38 +267,6 @@ export function CustomWorldCreationHub({
     [activeFilter, shelfItems],
   );
 
-  function handleOpenShelfItem(item: CreationWorkShelfItem) {
-    switch (item.source.kind) {
-      case 'puzzle':
-        onOpenPuzzleDetail?.(item.source.item);
-        return;
-      case 'baby-object-match':
-        onOpenBabyObjectMatchDetail?.(item.source.item);
-        return;
-      case 'visual-novel':
-        onOpenVisualNovelDetail?.(item.source.item);
-        return;
-      case 'big-fish':
-        onOpenBigFishDetail?.(item.source.item);
-        return;
-      case 'match3d':
-        onOpenMatch3DDetail?.(item.source.item);
-        return;
-      case 'square-hole':
-        onOpenSquareHoleDetail?.(item.source.item);
-        return;
-      case 'rpg':
-        if (item.status === 'draft') {
-          onOpenDraft(item.source.item);
-          return;
-        }
-
-        if (item.source.item.profileId) {
-          onEnterPublished(item.source.item.profileId);
-        }
-    }
-  }
-
   function buildDeleteAction(item: CreationWorkShelfItem) {
     if (!item.canDelete) {
       return null;