feat(browser): rework element annotation and picker toolbar

Element annotation is now free-text: dropped the Fix/Change/Question/
Approve intent pills and the intent field, so the user just says what
they want. The card uses the shared Button and is titled "Annotate
element".

Toolbar: the element picker and DevTools are no longer dev-gated and
work in prod; DevTools uses a wrench icon, and the old clipboard "grab"
is now a Camera "Screenshot element" tool. Each toolbar button
highlights only its own mode, and the copy toast reflects whether a
screenshot image was actually captured.

packages/app/src/i18n/resources/zh-CN.ts

@@ -422,22 +422,17 @@ export const zhCN: TranslationResources = {
         enterUrl: "输入 URL",
         openDevTools: "打开浏览器开发者工具",
         cancelSelector: "取消元素选择器",
-        selectElement: "选择元素",
-        grabElement: "复制元素到剪贴板",
-        grabElementLabel: "元素",
-        grabFailed: "复制元素失败",
+        annotateElement: "标注元素",
+        screenshotElement: "截图元素",
+        screenshotCopied: "已将截图复制到剪贴板",
+        elementCopied: "已将元素复制到剪贴板",
+        screenshotFailed: "无法复制截图",
       },
       annotate: {
-        title: "发送反馈给智能体",
-        placeholder: "描述需要修改的内容…",
+        title: "标注元素",
+        placeholder: "给智能体关于此元素的留言…",
         submit: "附加",
         cancel: "取消",
-        intents: {
-          fix: "修复",
-          change: "修改",
-          question: "提问",
-          approve: "认可",
-        },
       },
       devices: {
         label: "设备尺寸",