复用平台文本域收口生成提示词

编辑器画布内生成输入框和修改图片弹窗提示词改为复用 PlatformTextField。

删除编辑器按 textarea 标签选择器维护基础输入 chrome 的做法，仅保留局部尺寸与样式覆盖。

补充测试覆盖生成提示词共享文本域样式，并更新 TRACKING。

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

@@ -737,6 +737,11 @@ describe('ImageCanvasEditorView', () => {
     expect(
       within(generateDialog).getByRole('button', { name: '添加参考图' }).className,
     ).toContain('image-canvas-editor__generation-ref');
+    const generatePrompt = screen.getByLabelText('生成提示词');
+    expect(generatePrompt.className).toContain('platform-text-field');
+    expect(generatePrompt.className).toContain(
+      'image-canvas-editor__generation-prompt',
+    );
     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(
@@ -1077,7 +1082,10 @@ describe('ImageCanvasEditorView', () => {
     fireEvent.click(screen.getByRole('button', { name: '修改图片' }));
     const editDialog = screen.getByRole('dialog', { name: '修改图片' });
     expect(editDialog).toBeTruthy();
-    fireEvent.change(screen.getByLabelText('生成提示词'), {
+    const editPrompt = screen.getByLabelText('生成提示词');
+    expect(editPrompt.className).toContain('platform-text-field');
+    expect(editPrompt.className).toContain('image-canvas-editor__generate-prompt');
+    fireEvent.change(editPrompt, {
       target: { value: '把画面改成黄昏光线' },
     });
     fireEvent.click(screen.getByRole('button', { name: '修改' }));