收口元数据角标图标按钮

PlatformIconButton 增加 spanButton 形态，支持嵌套动作面合法复用图标按钮 chrome。

编辑器生成图元数据角标改为复用 PlatformIconButton，移除局部键盘处理。

补充测试覆盖 spanButton 键盘触发和元数据角标平台样式，并更新 TRACKING。

TRACKING.md

@@ -98,3 +98,4 @@
 - 2026-06-14 组件复用修正：编辑器 `EditorIconButton` 改为委托 `PlatformIconButton` 的薄包装，保留编辑器局部 class 与调用方式，但不再维护重复的原生图标按钮可访问性和基础 chrome；验证命令：`npm run test -- src/components/image-editor/ImageCanvasEditorPrimitives.test.tsx src/components/image-editor/ImageCanvasEditorView.test.tsx src/components/common/PlatformIconButton.test.tsx`、`npm run typecheck`。
 - 2026-06-14 组件复用修正：编辑器生成输入框的提交按钮改为复用 `PlatformActionButton`，仅保留生成器局部尺寸和 Lovart 式浅灰覆盖，不再直接维护原生 submit 按钮基础 chrome；验证命令：`npm run test -- src/components/image-editor/ImageCanvasEditorView.test.tsx src/components/common/PlatformActionButton.test.tsx`、`npm run typecheck`。
 - 2026-06-14 组件复用修正：编辑器生成输入框的“参考图”按钮改为复用 `PlatformIconButton variant="surfaceFloating"`，用 children 承载短标签，仅保留生成器局部尺寸和浅灰覆盖；验证命令：`npm run test -- src/components/image-editor/ImageCanvasEditorView.test.tsx src/components/common/PlatformIconButton.test.tsx`、`npm run typecheck`。
+- 2026-06-14 组件复用修正：编辑器生成图右上角元数据角标改为复用 `PlatformIconButton asChild="spanButton"`，保留嵌套在图层按钮内的合法 DOM 结构，同时把 Enter / Space 键盘触发和 `darkMini` chrome 收口到共享组件；验证命令：`npm run test -- src/components/common/PlatformIconButton.test.tsx src/components/image-editor/ImageCanvasEditorView.test.tsx`、`npm run typecheck`。

src/components/common/PlatformIconButton.test.tsx

@@ -1,7 +1,7 @@
 /* @vitest-environment jsdom */
 
-import { render, screen } from '@testing-library/react';
-import { expect, test } from 'vitest';
+import { fireEvent, render, screen } from '@testing-library/react';
+import { expect, test, vi } from 'vitest';
 
 import { PlatformIconButton } from './PlatformIconButton';
 
@@ -95,6 +95,34 @@ test('supports dark mini icon action chrome', () => {
   expect(button.textContent).toBe('?');
 });
 
+test('supports span button child chrome for nested action surfaces', () => {
+  const onClick = vi.fn();
+  render(
+    <button type="button">
+      <PlatformIconButton
+        asChild="spanButton"
+        label="查看元数据"
+        variant="darkMini"
+        icon={<span aria-hidden="true">{'{}'}</span>}
+        className="absolute"
+        onClick={onClick}
+      />
+    </button>,
+  );
+
+  const action = screen.getByRole('button', { name: '查看元数据' });
+
+  expect(action.tagName).toBe('SPAN');
+  expect(action.className).toContain('bg-black/55');
+  expect(action.className).toContain('absolute');
+  expect(action.getAttribute('tabindex')).toBe('0');
+
+  fireEvent.keyDown(action, { key: 'Enter' });
+  fireEvent.keyDown(action, { key: ' ' });
+
+  expect(onClick).toHaveBeenCalledTimes(2);
+});
+
 test('supports label child chrome for icon upload controls', () => {
   const { container } = render(
     <>

src/components/common/PlatformIconButton.tsx

@@ -1,5 +1,7 @@
 import type {
   ButtonHTMLAttributes,
+  HTMLAttributes,
+  KeyboardEvent,
   LabelHTMLAttributes,
   ReactNode,
 } from 'react';
@@ -27,9 +29,19 @@ type PlatformIconButtonLabelProps = Omit<
     asChild: 'label';
   };
 
+type PlatformIconButtonSpanButtonProps = Omit<
+  HTMLAttributes<HTMLSpanElement>,
+  'aria-label' | 'children' | 'role'
+> &
+  PlatformIconButtonBaseProps & {
+    asChild: 'spanButton';
+    disabled?: boolean;
+  };
+
 type PlatformIconButtonProps =
   | PlatformIconButtonButtonProps
-  | PlatformIconButtonLabelProps;
+  | PlatformIconButtonLabelProps
+  | PlatformIconButtonSpanButtonProps;
 
 /**
  * 平台通用图标动作按钮。
@@ -71,6 +83,45 @@ export function PlatformIconButton({
     );
   }
 
+  if (asChild === 'spanButton') {
+    const {
+      disabled,
+      onClick,
+      onKeyDown,
+      tabIndex,
+      ...spanProps
+    } = actionProps as HTMLAttributes<HTMLSpanElement> & {
+      disabled?: boolean;
+    };
+    const handleKeyDown = (event: KeyboardEvent<HTMLSpanElement>) => {
+      onKeyDown?.(event);
+      if (event.defaultPrevented || disabled) {
+        return;
+      }
+      if (event.key === 'Enter' || event.key === ' ') {
+        event.preventDefault();
+        event.currentTarget.click();
+      }
+    };
+
+    return (
+      <span
+        {...spanProps}
+        aria-disabled={disabled}
+        aria-label={label}
+        className={actionClassName}
+        onClick={disabled ? undefined : onClick}
+        onKeyDown={handleKeyDown}
+        role="button"
+        tabIndex={disabled ? -1 : (tabIndex ?? 0)}
+        title={title}
+      >
+        {icon}
+        {children}
+      </span>
+    );
+  }
+
   const { type = 'button', ...buttonProps } =
     actionProps as ButtonHTMLAttributes<HTMLButtonElement>;
 

src/components/image-editor/ImageCanvasEditorView.test.tsx

@@ -1064,6 +1064,10 @@ describe('ImageCanvasEditorView', () => {
     if (!metadataCornerButton) {
       throw new Error('metadata corner button should exist');
     }
+    expect(metadataCornerButton.className).toContain('bg-black/55');
+    expect(metadataCornerButton.className).toContain(
+      'image-canvas-editor__metadata-corner',
+    );
     fireEvent.click(metadataCornerButton);
 
     const metadataDialog = screen.getByRole('dialog', { name: /生成图片 .*元数据/ });

src/components/image-editor/ImageCanvasEditorView.tsx

@@ -2550,28 +2550,19 @@ export function ImageCanvasEditorView() {
                   >
                     <img src={layer.src} alt={`画布图片：${layer.title}`} />
                     {isGeneratedLayer(layer) ? (
-                      <span
+                      <PlatformIconButton
+                        asChild="spanButton"
+                        variant="darkMini"
                         className="image-canvas-editor__metadata-corner"
-                        role="button"
-                        tabIndex={0}
-                        aria-label={`查看${layer.title}元数据`}
+                        label={`查看${layer.title}元数据`}
+                        icon={<Braces className="h-3 w-3" />}
                         onClick={(event) => {
                           event.stopPropagation();
                           setMetadataLayer(layer);
                           selectSingleLayer(layer.id);
                         }}
                         onPointerDown={(event) => event.stopPropagation()}
-                        onKeyDown={(event) => {
-                          if (event.key === 'Enter' || event.key === ' ') {
-                            event.preventDefault();
-                            event.stopPropagation();
-                            setMetadataLayer(layer);
-                            selectSingleLayer(layer.id);
-                          }
-                        }}
-                      >
-                        <Braces className="h-3 w-3" />
-                      </span>
+                      />
                     ) : null}
                     {isHovered ? (
                       <span className="image-canvas-editor__size-badge">