🐛 [Bug]: Mention 组件 在内容中输入触发字符不生效

### Version

1.0.1

### Vue Version

3.2

### Link to minimal reproduction

https://vue-devui.github.io/components/mention/#%E5%9F%BA%E6%9C%AC%E7%94%A8%E6%B3%95

### Step to reproduce

1. 输入文字xx
2. 追加输入触发字符@

### What is expected

应触发hint

### What is actually happening

未触发hint

### Any additional comments (optional)

_No response_