[Bug] User settings get reset after chat sync

### Bug Description

User settings like `Show splash screen` or the default GPT model for new chats get reset every time I do a chat sync. The chat sync is configured to use Upstash.

### Steps to Reproduce

1. Go to Settings
2. Setup sync credentials if not configured
3. Change a default setting, e.g. Disable `Show splash screen on new chat`
4. Click `Sync`
5. The remote and local chats are now synced, however, the user settings are reset (e.g. `Show splash screen on new chat` is enabled)

### Expected Behavior

Either the user settings should be synced along with chat data, or preserve the local settings for every sync operation.

### Screenshots

_No response_

### Deployment Method

- [ ] Docker
- [X] Vercel
- [ ] Server

### Desktop OS

Windows, Linux, MacOS (tested all on these 3)

### Desktop Browser

Chrome

### Desktop Browser Version

_No response_

### Smartphone Device

_No response_

### Smartphone OS

_No response_

### Smartphone Browser

_No response_

### Smartphone Browser Version

_No response_

### Additional Logs

_No response_