## **Description**

This PR **completely refactors** the
`@metamask/design-system-twrnc-preset` package to focus on simplicity
and provide only the essential tooling needed for using `twrnc` with the
design system in React Native applications.

**What changed:**
- **Simplified theme system**: Removed complex `ColorSet`/`ColorScheme`
architecture in favor of a clean `Theme.Light`/`Theme.Dark` enum
- **Better encapsulation**: Moved `twrnc` from peer dependencies to
regular dependencies so consumers don't need to manage it
- **Removed file nesting**: Eliminated the `Theme/` folder structure and
`twrnc-settings/` complexity
- **Clean API surface**: Exports only essentials: `ThemeProvider`,
`Theme`, `useTailwind()`, and new `useTheme()` hook
- **Controlled components**: `ThemeProvider` is now a simple controlled
component instead of managing internal state
- **Removed unused files**: Removed `tailwind.config.js` and
`tailwind.config.d.ts` as they aren't used
* **Standard naming**: Renamed
`[Theme/Theme.utilities.ts](https://github.com/MetaMask/metamask-design-system/pull/722/files#diff-85c440c866d00e849e6beccc82c3cd6925caea6f0b4881edf5d1e2cf8b01b4a8)`
to `tailwind.config.ts` to follow expected conventions, as this file
generates the Tailwind config.
* **Source of Truth for linting**: Updated prettier to point to
`apps/storybook-react-native/tailwind-intellisense.config.js` to align
intellisense and linting settings

**Why this improves the developer experience:**
- **Easier to use**: Single `theme` prop instead of multiple
configuration concepts
- **More predictable**: Consumers control theme logic (system detection
moved to Storybook level)
- **Better separation**: Package handles styling, consumers handle theme
detection
- **Cleaner imports**: Only import what you need without complex nested
structures

## **Related issues**

Fixes: #719
#720

## **Manual testing steps**

1. Check updated theme provider in `storybook-react-native`
```yarn storybook:ios```
2. Navigate to the Wallet Home story which uses both the provider and useTailwind hook
3. Check `ButtonPrimary` stays in light mode in both light and dark mode
4. Check implementation of publish preview from this PR in mobile MetaMask/metamask-mobile#16103

## **Screenshots/Recordings**

### **Before**
- Complex API: `<ThemeProvider colorSet={ColorSet.Brand} theme={Theme.Default}>` (no usage of `ThemeContext`, `ThemeContextProps`, `ThemeProviderProps`, etc)
- Multiple nested folders and exports
- Consumers managed `twrnc` dependency
`useColorScheme` was handled internally in the ThemeProvider based on light, dark, default

https://github.com/user-attachments/assets/eb365979-3eec-4559-9f65-84901e8b78f4

### **After** 
- Simple API: `<ThemeProvider theme={theme}>`
- Flat file structure with essential exports only  
- Package owns `twrnc` dependency internally
- Theme state has been offloaded to storybook

https://github.com/user-attachments/assets/4cdfad8a-8ead-495e-9231-ff60eecb38a9

[Preview package](#722 (comment)) working in mobile MetaMask/metamask-mobile#16103

https://github.com/user-attachments/assets/88d443ff-7c49-44f7-9c00-042323b1a35f

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor Docs](https://github.com/MetaMask/contributor-docs)
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format if applicable
- [x] I've applied the right labels on the PR (see [labeling guidelines](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/LABELING_GUIDELINES.md)). Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.