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.tsx

@@ -2839,14 +2839,17 @@ export function ImageCanvasEditorView() {
                   GPT Im...
                   <ChevronDown className="h-3 w-3" />
                 </button>
-                <button
+                <PlatformActionButton
                   type="submit"
+                  tone="secondary"
+                  size="xs"
+                  shape="pill"
                   className="image-canvas-editor__generation-submit"
                   disabled={generateDialog.status === 'generating'}
                   aria-label="生成"
                 >
                   {generateDialog.status === 'generating' ? '生成中' : '12'}
-                </button>
+                </PlatformActionButton>
               </div>
               {generateDialog.status === 'generating' ? (
                 <PlatformStatusMessage