拆分图片画布顶部栏视图

新增 ImageCanvasTopbarView 承载返回项目入口和项目标题区域

新增顶栏视图测试覆盖重命名和导出入口

精简 ImageCanvasEditorView 的顶部栏 JSX

更新图片画布拆分计划和 TRACKING 验证记录

src/components/image-editor/ImageCanvasTopbarView.tsx

@@ -0,0 +1,149 @@
+import { Check, ChevronLeft, Download, Pencil, X } from 'lucide-react';
+
+import { PlatformStatusMessage } from '../common/PlatformStatusMessage';
+import { PlatformTextField } from '../common/PlatformTextField';
+import { EditorIconButton } from './ImageCanvasEditorPrimitives';
+import type { CanvasLayer } from './ImageCanvasEditorTypes';
+import type { AssetExportStatus } from './useImageCanvasAssetExportWorkflow';
+
+type ImageCanvasTopbarViewProps = {
+  projectId: string | null;
+  projectTitle: string;
+  projectRenameValue: string;
+  isRenamingProject: boolean;
+  isProjectRenameSaving: boolean;
+  projectRenameError: string | null;
+  layers: CanvasLayer[];
+  assetExportStatus: AssetExportStatus | null;
+  isExportingAssets: boolean;
+  setProjectRenameValue: (value: string) => void;
+  startProjectRename: () => void;
+  cancelProjectRename: () => void;
+  submitProjectRename: (projectId: string | null) => void;
+  resetProjectRenameError: () => void;
+  exportCanvasAssets: () => void | Promise<void>;
+};
+
+export function ImageCanvasTopbarView({
+  projectId,
+  projectTitle,
+  projectRenameValue,
+  isRenamingProject,
+  isProjectRenameSaving,
+  projectRenameError,
+  layers,
+  assetExportStatus,
+  isExportingAssets,
+  setProjectRenameValue,
+  startProjectRename,
+  cancelProjectRename,
+  submitProjectRename,
+  resetProjectRenameError,
+  exportCanvasAssets,
+}: ImageCanvasTopbarViewProps) {
+  const hasExportableLayer = layers.some(
+    (layer) => layer.src.trim().length > 0,
+  );
+
+  return (
+    <div className="image-canvas-editor__topbar">
+      <a
+        className="image-canvas-editor__project-back-button"
+        href="/project"
+        aria-label="返回项目页面"
+        title="返回项目"
+      >
+        <ChevronLeft className="h-4 w-4" aria-hidden="true" />
+      </a>
+      <div className="image-canvas-editor__title-block">
+        {isRenamingProject ? (
+          <form
+            className="image-canvas-editor__project-title-form"
+            onSubmit={(event) => {
+              event.preventDefault();
+              submitProjectRename(projectId);
+            }}
+          >
+            <PlatformTextField
+              aria-label="项目名称"
+              value={projectRenameValue}
+              autoFocus
+              disabled={isProjectRenameSaving}
+              className="image-canvas-editor__project-title-input"
+              onChange={(event) => {
+                setProjectRenameValue(event.target.value);
+                resetProjectRenameError();
+              }}
+              onKeyDown={(event) => {
+                if (event.key === 'Escape') {
+                  event.preventDefault();
+                  cancelProjectRename();
+                }
+              }}
+            />
+            <EditorIconButton
+              type="submit"
+              label="保存项目名称"
+              title="保存"
+              icon={Check}
+              disabled={isProjectRenameSaving}
+            />
+            <EditorIconButton
+              label="取消修改项目名称"
+              title="取消"
+              icon={X}
+              disabled={isProjectRenameSaving}
+              onClick={cancelProjectRename}
+            />
+            {projectRenameError ? (
+              <span
+                className="image-canvas-editor__project-title-error"
+                role="alert"
+              >
+                {projectRenameError}
+              </span>
+            ) : null}
+          </form>
+        ) : (
+          <div className="image-canvas-editor__project-title-row">
+            <button
+              type="button"
+              className="image-canvas-editor__project-title-button"
+              onDoubleClick={startProjectRename}
+              aria-label={`编辑项目名称${projectTitle}`}
+            >
+              <h1>{projectTitle}</h1>
+            </button>
+            <EditorIconButton
+              className="image-canvas-editor__project-rename-button"
+              label="编辑项目名称"
+              title="编辑项目名称"
+              icon={Pencil}
+              onClick={startProjectRename}
+            />
+          </div>
+        )}
+        <span>画布</span>
+      </div>
+      <div className="image-canvas-editor__topbar-actions">
+        <EditorIconButton
+          label="下载画布素材"
+          title="下载画布素材"
+          icon={Download}
+          disabled={isExportingAssets || !hasExportableLayer}
+          onClick={() => void exportCanvasAssets()}
+        />
+        {assetExportStatus ? (
+          <PlatformStatusMessage
+            tone={assetExportStatus.tone}
+            surface="platform"
+            size="xs"
+            role={assetExportStatus.tone === 'error' ? 'alert' : 'status'}
+          >
+            {assetExportStatus.message}
+          </PlatformStatusMessage>
+        ) : null}
+      </div>
+    </div>
+  );
+}