复用平台按钮收口生成提交

编辑器生成输入框提交按钮改为 PlatformActionButton。

保留生成器局部尺寸和浅灰覆盖，删除重复原生 submit 基础样式。

补充测试覆盖生成按钮平台按钮 class，并更新 TRACKING。

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

@@ -733,6 +733,12 @@ describe('ImageCanvasEditorView', () => {
     expect(within(generateDialog).getByText('参考图')).toBeTruthy();
     expect(within(generateDialog).getByRole('button', { name: '生成比例 1:1 2k 1张' })).toBeTruthy();
     expect(within(generateDialog).getByRole('button', { name: '生成模型 GPT Image' })).toBeTruthy();
+    expect(within(generateDialog).getByRole('button', { name: '生成' }).className).toContain(
+      'platform-button',
+    );
+    expect(within(generateDialog).getByRole('button', { name: '生成' }).className).toContain(
+      'image-canvas-editor__generation-submit',
+    );
     expect(screen.queryByRole('toolbar', { name: 'AI画布工具栏' })).toBeNull();
 
     fireEvent.change(screen.getByLabelText('生成提示词'), {