### What problem does this PR solve?
Refactor: UmiJs -> Vite+React
### Type of change
- [x] Refactoring
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Co-authored-by: Liu An <asiro@qq.com>
### What problem does this PR solve?
Feat: Users can chat directly without first creating a conversation.
#11768
### Type of change
- [x] New Feature (non-breaking change which adds functionality)