Increase VectorEngine timeouts and add image UI

Add VectorEngine image generation config and raise request timeouts (env + scripts) from 180000 to 1000000ms. Introduce a reusable CreativeImageInputPanel component with tests and wire up mobile keyboard-focus helpers; update generation views and related tests (CustomWorldGenerationView, BarkBattle editor, Match3D, Puzzle flows). Improve API error handling / VectorEngine request guidance (packages/shared http.ts and docs), and apply multiple backend/frontend fixes for puzzle/match3d/prompt handling. Also include extensive docs and decision-log updates describing UI/UX decisions and verification steps.

src/components/puzzle-runtime/PuzzleRuntimeShell.test.tsx

@@ -372,6 +372,117 @@ test('指针拖拽合并大块时按大块锚点提交拖拽', () => {
   });
 });
 
+test('拖拽合并大块时底层单格不显示选中色块', () => {
+  const originalRequestAnimationFrame = window.requestAnimationFrame;
+  const originalCancelAnimationFrame = window.cancelAnimationFrame;
+  const mergedRun: PuzzleRunSnapshot = {
+    ...clearedRun,
+    currentLevel: {
+      ...clearedRun.currentLevel!,
+      status: 'playing',
+      startedAtMs: Date.now(),
+      remainingMs: 300_000,
+      timeLimitMs: 300_000,
+      board: {
+        ...clearedRun.currentLevel!.board,
+        allTilesResolved: false,
+        mergedGroups: [
+          {
+            groupId: 'group-large',
+            pieceIds: ['piece-0', 'piece-1', 'piece-3'],
+            occupiedCells: [
+              { row: 0, col: 0 },
+              { row: 0, col: 1 },
+              { row: 1, col: 0 },
+            ],
+          },
+        ],
+        pieces: clearedRun.currentLevel!.board.pieces.map((piece) =>
+          ['piece-0', 'piece-1', 'piece-3'].includes(piece.pieceId)
+            ? { ...piece, mergedGroupId: 'group-large' }
+            : piece,
+        ),
+      },
+    },
+  };
+
+  Object.defineProperty(window, 'requestAnimationFrame', {
+    configurable: true,
+    value: vi.fn(() => 1),
+  });
+  Object.defineProperty(window, 'cancelAnimationFrame', {
+    configurable: true,
+    value: vi.fn(),
+  });
+
+  const { container, unmount } = renderPuzzleRuntime(
+    <PuzzleRuntimeShell
+      run={mergedRun}
+      onBack={vi.fn()}
+      onSwapPieces={vi.fn()}
+      onDragPiece={vi.fn()}
+      onAdvanceNextLevel={vi.fn()}
+    />,
+  );
+  const board = container.querySelector(
+    '[data-testid="puzzle-board"]',
+  ) as HTMLElement | null;
+  if (!board) {
+    throw new Error('缺少测试棋盘');
+  }
+  board.getBoundingClientRect = () =>
+    ({
+      x: 0,
+      y: 0,
+      left: 0,
+      top: 0,
+      right: 300,
+      bottom: 300,
+      width: 300,
+      height: 300,
+      toJSON: () => ({}),
+    }) as DOMRect;
+  const mergedPiece = container.querySelector(
+    '[data-merged-piece-outline="true"]',
+  ) as HTMLElement | null;
+  if (!mergedPiece) {
+    throw new Error('缺少测试合并拼图片');
+  }
+
+  act(() => {
+    dispatchPointerEvent(mergedPiece, 'pointerdown', {
+      pointerId: 13,
+      clientX: 60,
+      clientY: 60,
+    });
+  });
+  act(() => {
+    dispatchPointerEvent(mergedPiece, 'pointermove', {
+      pointerId: 13,
+      clientX: 210,
+      clientY: 210,
+    });
+  });
+
+  const basePiece = container.querySelector(
+    '[data-piece-id="piece-0"]',
+  ) as HTMLElement | null;
+  expect(basePiece?.className).toContain('puzzle-runtime-piece--merged');
+  expect(basePiece?.className).not.toContain(
+    'puzzle-runtime-piece--selected',
+  );
+
+  unmount();
+  Object.defineProperty(window, 'requestAnimationFrame', {
+    configurable: true,
+    value: originalRequestAnimationFrame,
+  });
+  Object.defineProperty(window, 'cancelAnimationFrame', {
+    configurable: true,
+    value: originalCancelAnimationFrame,
+  });
+});
+
 test('通关后显示结算弹窗、排行榜和下一关按钮', () => {
   vi.useFakeTimers();
   const onAdvanceNextLevel = vi.fn();