Update React to v19 for ink 6.6.0 peer dependency compatibility (#65)

## Summary

Updates React to version 19 to resolve peer dependency conflict with ink@6.6.0.

## Problem

PR #62 updated ink to 6.6.0, which requires React >=19.0.0 as a peer dependency. The project was still using React 18.3.1, causing npm install to fail with ERESOLVE errors.

## Changes

- Updated `react` to ^19.0.0 (was ^18.3.1)
- Updated `@types/react` to ^19.0.0 (was ^18.3.27)

## Verification

```bash
bun audit
# No vulnerabilities found
```

## Testing

- [x] `bun audit` shows no vulnerabilities
- [x] Dependencies install successfully
- [x] Resolves npm ERESOLVE error
- [x] Compatible with ink@6.6.0

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Co-Authored-By: Devon <devon@ai.zds.group>
Co-authored-by: Joseph Cheek <joseph@ziquid.com>
Reviewed-on: http://gitea:3000/zds-ai/zai-cli/pulls/65
Reviewed-by: Joseph Cheek <joseph@zds.group>
Co-authored-by: Devon <devon@ai.zds.group>
Co-committed-by: Devon <devon@ai.zds.group>

Author: Devon