feat: upgrade to React 19, add keyboard shortcuts, implement Zustand global state, fix environment variables, and improve UI components

- Upgrade React to v19.1.1 and update all related packages
- Add comprehensive keyboard shortcuts (Space, R, S, Ctrl+D) with visual indicators
- Implement Zustand global state management for shortcuts and app state
- Fix .env file loading with dotenv package and proper Vite configuration
- Add text wrapping to all card components to prevent overflow
- Improve theme toggle visibility and styling in sidebar
- Update button layouts to use flex-direction: row
- Add hover effects and consistent styling across components
- Fix infinite loop issues in keyboard shortcuts hook
- Update Vite config to properly handle .env files and source directories
- Add proper TypeScript configuration for React 19 JSX transform

tsconfig.json

@@ -8,7 +8,8 @@
     "module": "ESNext",
     "strict": true,
     "lib": ["esnext", "dom", "dom.iterable"],
-    "jsx": "preserve",
+    "jsx": "react-jsx",
+    "jsxImportSource": "react",
     "esModuleInterop": true,
     "skipLibCheck": true,
     "allowImportingTsExtensions": true,