布局重构:

- 预览改为全区域背景层。
  - 左右面板、顶部流程条改为覆盖层，可遮挡预览。
  - 左右面板开合状态仅保存在当前 React 会话。
  - 增加左右面板“收起/展开”入口。
  - 编辑器关闭入口改为单独的 ×，继续通过 onBack 注入关闭逻辑。
  - 保留全局顶部栏与现有快捷键、业务状态、保存流程。
  - 底层页面仍由现有父级路由控制，不新增 URL 状态。

apps/ai-game-creator-shell/src/view/ui-editor/index.tsx

@@ -1,4 +1,4 @@
-import { ChevronLeft, Redo2, Undo2 } from 'lucide-react';
+import { Redo2, Undo2, X } from 'lucide-react';
 import { type ReactNode, useEffect, useMemo, useState } from 'react';
 
 import { ThemedModal } from '../../components/modal/ThemedModal';
@@ -71,6 +71,8 @@ export default function UiEditorPage({
   const [generateAfterWarning, setGenerateAfterWarning] = useState(false);
   const [generateSuccess, setGenerateSuccess] = useState<string | null>(null);
   const [returnConfirmOpen, setReturnConfirmOpen] = useState(false);
+  const [leftPanelOpen, setLeftPanelOpen] = useState(true);
+  const [rightPanelOpen, setRightPanelOpen] = useState(true);
   const saveDisabled =
     session.save.isSaving ||
     session.save.isGenerating ||
@@ -162,16 +164,16 @@ export default function UiEditorPage({
   }
 
   return (
-    <main className="flex h-full min-h-0 min-w-0 flex-col overflow-hidden bg-(--platform-body-fill) text-(--platform-text-strong)">
+    <main className="relative flex h-full min-h-0 min-w-0 flex-col overflow-hidden bg-(--platform-body-fill) text-(--platform-text-strong)">
       {resourceId ? (
         <header className="flex shrink-0 flex-wrap items-center justify-between gap-2 border-b border-(--platform-subpanel-border) bg-(--platform-subpanel-fill) px-4 py-2">
           <button
             type="button"
-            className="inline-flex items-center gap-1 rounded-lg px-2 py-1.5 text-sm hover:bg-black/4"
+            aria-label="关闭 UI 编辑器"
+            className="rounded-lg p-1.5 hover:bg-black/4"
             onClick={requestBack}
           >
-            <ChevronLeft size={17} aria-hidden="true" />
-            返回资源
+            <X size={18} aria-hidden="true" />
           </button>
           <strong className="text-sm">{resourceLabel ?? 'UI 设计'}</strong>
           <div className="game-workbench-editor-actions">
@@ -244,44 +246,69 @@ export default function UiEditorPage({
           {generateSuccess}
         </div>
       ) : null}
-      <ToolNavigation
-        activeStep={session.workflow.activeStep}
-        furthestStepIndex={session.workflow.furthestStepIndex}
-        disabled={session.workflow.isBusy}
-        onChange={session.workflow.requestStepChange}
-      />
-      <div className="grid min-h-0 min-w-0 flex-1 grid-cols-[minmax(0,24fr)_minmax(0,44fr)_minmax(0,32fr)] overflow-hidden">
-        <InputSidebar input={session.input} />
-        <div className="flex min-h-0 min-w-0 flex-col overflow-hidden">
-          <WorkflowActionCard workflow={session.workflow} />
-          <PreviewWorkspace canvas={session.canvas} />
+      <div className="absolute inset-0 min-h-0 min-w-0 overflow-hidden">
+        <PreviewWorkspace canvas={session.canvas} />
+      </div>
+      <div className="pointer-events-none absolute inset-0 z-10">
+        <div className="pointer-events-auto absolute left-0 top-0 w-[min(24rem,24vw)] max-w-[24rem] overflow-hidden">
+          {leftPanelOpen ? <InputSidebar input={session.input} /> : null}
+          <button
+            type="button"
+            className="absolute right-1 top-1 rounded bg-(--platform-subpanel-fill)/90 px-2 py-1 text-xs"
+            onClick={() => setLeftPanelOpen((value) => !value)}
+          >
+            {leftPanelOpen ? '收起' : '展开'}
+          </button>
         </div>
-        <div className="flex min-h-0 min-w-0 flex-col overflow-hidden">
-          {session.input.activeStep === 'structure-recognition' ? (
-            <RecognitionOverview
-              uiTrees={session.input.uiTrees}
-              onFocusStatusNode={(treeId, nodeId) => {
-                session.input.focusNode(treeId, nodeId);
-                session.input.highlightStatusField(nodeId, 'layout_status');
-              }}
-            />
-          ) : session.input.activeStep === 'asset-separation' ? (
-            <SeparationOverview
-              uiTrees={session.input.uiTrees}
-              sprites={session.input.sprites}
-              onFocusStatusNode={(treeId, nodeId) => {
-                session.input.focusNode(treeId, nodeId);
-                session.input.highlightStatusField(nodeId, 'component_status');
-              }}
-            />
-          ) : (
-            <ImportOverview
-              images={session.input.images}
-              sprites={session.input.sprites}
-              uiTrees={session.input.uiTrees}
-            />
-          )}
-          <InspectorSidebar inspector={session.inspector} />
+        <div className="pointer-events-auto absolute left-1/2 top-0 w-[min(44rem,44vw)] -translate-x-1/2">
+          <ToolNavigation
+            activeStep={session.workflow.activeStep}
+            furthestStepIndex={session.workflow.furthestStepIndex}
+            disabled={session.workflow.isBusy}
+            onChange={session.workflow.requestStepChange}
+          />
+          <WorkflowActionCard workflow={session.workflow} />
+        </div>
+        <div className="pointer-events-auto absolute right-0 top-0 w-[min(32rem,32vw)] max-w-[32rem] overflow-hidden">
+          {rightPanelOpen ? (
+            <>
+              {session.input.activeStep === 'structure-recognition' ? (
+                <RecognitionOverview
+                  uiTrees={session.input.uiTrees}
+                  onFocusStatusNode={(treeId, nodeId) => {
+                    session.input.focusNode(treeId, nodeId);
+                    session.input.highlightStatusField(nodeId, 'layout_status');
+                  }}
+                />
+              ) : session.input.activeStep === 'asset-separation' ? (
+                <SeparationOverview
+                  uiTrees={session.input.uiTrees}
+                  sprites={session.input.sprites}
+                  onFocusStatusNode={(treeId, nodeId) => {
+                    session.input.focusNode(treeId, nodeId);
+                    session.input.highlightStatusField(
+                      nodeId,
+                      'component_status',
+                    );
+                  }}
+                />
+              ) : (
+                <ImportOverview
+                  images={session.input.images}
+                  sprites={session.input.sprites}
+                  uiTrees={session.input.uiTrees}
+                />
+              )}
+              <InspectorSidebar inspector={session.inspector} />
+            </>
+          ) : null}
+          <button
+            type="button"
+            className="absolute left-1 top-1 rounded bg-(--platform-subpanel-fill)/90 px-2 py-1 text-xs"
+            onClick={() => setRightPanelOpen((value) => !value)}
+          >
+            {rightPanelOpen ? '收起' : '展开'}
+          </button>
         </div>
       </div>
       <EditorDialogs dialogs={session.dialogs} />