N UI 281 general color scheme options (#102)

Since some have complained about the colors being too "aggressive,"
there's now the option to change the THEME.

---
For **now**, there are only two:
- **redeye**: acidic colors
- **boring**: more institutional colors. You can present it to your BOSS.

---
To change the THEME, there are two options:

### 1) Edit the config.json file in the frontend
- Locate the "dist/config.json" file in the frontend
- Open and change the "theme" parameter in the JSON.
- Allowed parameters are: "redeye" or "boring."
For example:
```json
{
   "theme": "boring"
}
```
- At this point, the color theme should change when the app is restarted.
> We'll probably find a solution in the future that makes it easier to locate this file.

### 2) Set directly from the UI
- Open the "HELP" card
- Change the "Theme" property
- The new selected theme is stored in "localStorage."
<img width="703" height="581" alt="image" src="https://github.com/user-attachments/assets/8133c8df-d7e2-4d67-9dc0-ab0c74e33bb2" />