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.tsx

@@ -71,6 +71,7 @@ import {
 } from '../common/PlatformFloatingMenu';
 import { PlatformIconButton } from '../common/PlatformIconButton';
 import { PlatformStatusMessage } from '../common/PlatformStatusMessage';
+import { PlatformTextField } from '../common/PlatformTextField';
 import { UnifiedModal } from '../common/UnifiedModal';
 
 type EditorAsset = {
@@ -2786,11 +2787,15 @@ export function ImageCanvasEditorView() {
               >
                 <span>参考图</span>
               </PlatformIconButton>
-              <textarea
+              <PlatformTextField
+                variant="textarea"
                 aria-label="生成提示词"
                 value={generateDialog.prompt}
                 disabled={generateDialog.status === 'generating'}
                 placeholder="今天我们要创作什么"
+                size="sm"
+                density="compact"
+                className="image-canvas-editor__generation-prompt"
                 onChange={(event) =>
                   setGenerateDialog((currentDialog) =>
                     currentDialog
@@ -2934,10 +2939,14 @@ export function ImageCanvasEditorView() {
             }}
           >
             <div className="image-canvas-editor__generate-body">
-              <textarea
+              <PlatformTextField
+                variant="textarea"
                 aria-label="生成提示词"
                 value={generateDialog.prompt}
                 disabled={generateDialog.status === 'generating'}
+                size="sm"
+                density="roomy"
+                className="image-canvas-editor__generate-prompt"
                 placeholder={
                   generateDialog.mode === 'edit'
                     ? '描述你想如何修改这张图片'