docs(copilot): enhance instructions with Bun requirements and development standards

Expands Copilot instructions to enforce critical Bun-first package management workflow and prevent usage of npm/yarn/npx commands.

Adds comprehensive sections covering:
- Runtime and tooling stack details with Bun as primary runtime
- Explicit package management commands to prevent npm/yarn usage
- Performance optimization guidelines leveraging Bun's capabilities
- Testing approach using Bun's built-in test runner
- Enhanced coding standards and API integration patterns
- Cross-platform development considerations for mobile and TV

Improves developer onboarding by providing clearer context about project architecture, offline capabilities, and Chromecast support in the overview.

.github/copilot-instructions.md

@@ -3,58 +3,94 @@
 ## Project Overview
 
 Streamyfin is a cross-platform Jellyfin video streaming client built with Expo (React Native).  
-It supports mobile (iOS/Android) and TV platforms, and integrates with Jellyfin and Jellyseerr APIs.
+It supports mobile (iOS/Android) and TV platforms, integrates with Jellyfin and Jellyseerr APIs,
+and provides seamless media streaming with offline capabilities and Chromecast support.
 
 ## Main Technologies
 
-- React Native (Expo)
-- TypeScript
-- React Query
-- Jotai (state management)
-- Jellyfin SDK (TypeScript)
-- BiomeJS (code formatting/linting)
-- EAS (Expo Application Services)
-- Shell scripting (for automation)
-- GitHub Actions (CI/CD)
+- **Runtime**: Bun (JavaScript/TypeScript execution)
+- **Framework**: React Native (Expo)
+- **Language**: TypeScript (strict mode)
+- **State Management**: Jotai (global state) + React Query (server state)
+- **API SDK**: Jellyfin SDK (TypeScript)
+- **Navigation**: Expo Router (file-based routing)
+- **Code Quality**: BiomeJS (formatting/linting)
+- **Build Platform**: EAS (Expo Application Services)
+- **CI/CD**: GitHub Actions with Bun
+
+## Package Management
+
+**CRITICAL: ALWAYS use `bun` for all package management operations**
+
+- **NEVER use `npm`, `yarn` or `npx` commands**
+- Use `bun install` instead of `npm install` or `yarn install`
+- Use `bun add <package>` instead of `npm install <package>`
+- Use `bun remove <package>` instead of `npm uninstall <package>`
+- Use `bun run <script>` instead of `npm run <script>`
+- Use `bunx <command>` instead of `npx <command>`
+- For Expo: use `bunx create-expo-app` or `bunx @expo/cli`
 
 ## Code Structure
 
 - `app/` – Main application code (screens, navigation, etc.)
 - `components/` – Reusable UI components
 - `providers/` – Context and API providers (e.g., JellyfinProvider.tsx)
-- `utils/` – Utility functions and atoms
+- `utils/` – Utility functions and Jotai atoms
 - `assets/` – Images and static assets
 - `scripts/` – Automation scripts (Node.js, Bash)
 - `plugins/` – Expo/Metro plugins
-- `README.md` – Project documentation
 
-## Coding Conventions
+## Coding Standards
 
-- Use TypeScript for all new code.
-- Prefer functional React components.
-- Use hooks for state and side effects.
-- Use Jotai for global state.
-- Use React Query for data fetching/caching.
-- Use BiomeJS for formatting and linting.
-- Follow the established folder structure for screens/components.
+- Use TypeScript for ALL files (no .js files)
+- Use descriptive English names for variables, functions, and components
+- Prefer functional React components with hooks
+- Use Jotai atoms for global state management
+- Use React Query for server state and caching
+- Follow BiomeJS formatting and linting rules
+- Use `const` over `let`, avoid `var` entirely
+- Implement proper error boundaries
+- Use React.memo() for performance optimization
+- Handle both mobile and TV navigation patterns
 
-## API Usage
+## API Integration
 
-- Use the Jellyfin SDK for all server interactions.
-- Use the `apiAtom` and `userAtom` from `JellyfinProvider` for authenticated API calls.
-- For navigation, use `expo-router`.
+- Use Jellyfin SDK for all server interactions
+- Access authenticated APIs via `apiAtom` and `userAtom` from JellyfinProvider
+- Implement proper loading states and error handling
+- Use React Query for caching and background updates
+- Handle offline scenarios gracefully
+
+## Performance Optimization
+
+- Leverage Bun's superior runtime performance
+- Optimize FlatList components with proper props
+- Use lazy loading for non-critical components
+- Implement proper image caching strategies
+- Monitor bundle size and use tree-shaking effectively
+
+## Testing
+
+- Use Bun's built-in test runner when possible
+- Test files: `*.test.ts` or `*.test.tsx`
+- Run tests with: `bun test`
+- Mock external APIs in tests
+- Focus on testing business logic and custom hooks
 
 ## Commit Messages
 
-- Use [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) (e.g., `feat:`, `fix:`, `chore:`).
-- Example: `feat(player): add Chromecast support`
+Use [Conventional Commits](https://www.conventionalcommits.org/):
+Exemples:
+- `feat(player): add Chromecast support`
+- `fix(auth): handle expired JWT tokens`
+- `chore(deps): update Jellyfin SDK`
 
 ## Special Instructions
 
-- When suggesting code, prefer using existing atoms, hooks, and utility functions.
-- When adding new features, ensure they are accessible via both mobile and TV navigation if relevant.
-- When updating dependencies or scripts, check for compatibility with Expo and EAS.
-
----
+- Prioritize cross-platform compatibility (mobile + TV)
+- Ensure accessibility for TV remote navigation
+- Use existing atoms, hooks, and utilities before creating new ones
+- Maintain compatibility with Expo and EAS workflows
+- Always verify Bun compatibility when suggesting new dependencies
 
 **Copilot: Please use these instructions to provide context-aware suggestions and code completions for this repository.**