【BUG】Title: BUG Unable to click and switch models in web UI

English Version
Environment:

• PilotDeck version: v2026.09.09 (commit: d9ed2cd)
• Installation method: install.sh one-line install
• OS: macOS (darwin-arm64)
• Node.js version: v26.7.0
• Browser: Chrome/Safari (latest)
  Bug Description:
  In the Web UI chat input area, clicking the model selector does not switch models. There is no response after clicking, or the dropdown menu with available models does not appear.
  Steps to Reproduce:

1. Start the PilotDeck server
2. Open the Web UI in a browser
3. Locate the model selector in the chat input area (usually below or beside the input box)
4. Click the model selector to try switching models
   Expected Behavior:
   Clicking the model selector should display a list of available models, and selecting one should switch the current model.
   Actual Behavior:
   No response after clicking the model selector, or the dropdown menu cannot select.
   Related Code Locations:

• ui/src/components/chat/utils/globalModelSelection.ts - Global model selection state management
• ui/src/components/chat-v2/ComposerV2.tsx:701 - Model selection UI component

中文版
环境信息：

• PilotDeck 版本：v2026.09.09 (commit: d9ed2cd)
• 安装方式：install.sh 一键安装
• 操作系统：macOS (darwin-arm64)
• Node.js 版本：v26.7.0
• 浏览器：Chrome/Safari（最新版）
  Bug 描述：
  在 Web UI 的聊天输入区域，点击模型选择器（Model Selector）无法正常切换模型。点击后无响应，或下拉菜单不显示可选模型列表。
  复现步骤：

1. 启动 PilotDeck 服务
2. 打开浏览器访问 Web UI
3. 在聊天输入框找到模型选择器（通常位于输入框下方或侧边）
4. 点击模型选择器尝试切换模型
   预期行为：
   点击模型选择器后应显示可用模型列表，选择后应切换当前使用的模型。
   实际行为：
   点击模型选择器后下拉菜单无法选择。
   相关代码位置：

• ui/src/components/chat/utils/globalModelSelection.ts - 全局模型选择状态管理
• ui/src/components/chat-v2/ComposerV2.tsx:701 - 模型选择 UI 组件

Reproduce the issue in the Web UI using the listed macOS and browser setup, then inspect ui/src/components/chat-v2/ComposerV2.tsx around line 701 and ui/src/components/chat/utils/globalModelSelection.ts. Trace the click and selection state to determine why the available-model menu does not appear or apply a selection. Done means the selector opens, lists available models, and switches the current model after selection.