优化: 界面交互完善与设置体验

- 审批卡尊重滚动意图,等长切换回底,排队超时按钮修活
- 带图编辑提示不静默丢,删除目标回写,切换文案消歧
- 会话键盘可达+搜索态重命名,筛选计数口径对齐
- 子任务提示正名,看板加载态
- 主题跟随系统,表单脏态拦截,密钥显隐留空提示

src/i18n/en/ai.ts

@@ -43,6 +43,8 @@ export default {
     queueTimedOut: 'Queue timed out',
     approvalNotDelivered: 'Approval operation failed to reach the backend: {error}',
     queuedSendFailed: 'Failed to send queued message: {error}',
+    // UX-P2-A2: toast when queued messages get dropped by error/regenerate/edit (was silent)
+    queueCleared: 'Cleared {n} queued message(s)',
     approvalTimeout: '⚰ Approval timed out, automatically rejected: {toolName}',
     // conversation load/switch failure feedback (network jitter/IPC down → empty list/blank, was silent)
     loadConvFail: 'Failed to load conversations. Please check your network or backend connection.',