refactor: migrate to eslint flat config and format codebase with prettier

- Remove legacy .eslintrc.cjs and .eslintignore
- Add eslint.config.js with flat config, security rules (no-eval, no-implied-eval, no-new-func, no-script-url)
- Add .prettierrc and .prettierignore
- Format entire codebase with prettier

src/main.tsx

@@ -1,20 +1,20 @@
-import React from 'react'
-import ReactDOM from 'react-dom/client'
-import { BrowserRouter } from 'react-router-dom'
-import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import App from './App'
-import { ThemeColorsProvider } from './providers/ThemeColorsProvider'
-import { ToastProvider } from './components/Toast'
-import { initLogoPreload } from './api/branding'
-import { initTelegramWebApp } from './hooks/useTelegramWebApp'
-import './i18n'
-import './styles/globals.css'
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import { BrowserRouter } from 'react-router-dom';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import App from './App';
+import { ThemeColorsProvider } from './providers/ThemeColorsProvider';
+import { ToastProvider } from './components/Toast';
+import { initLogoPreload } from './api/branding';
+import { initTelegramWebApp } from './hooks/useTelegramWebApp';
+import './i18n';
+import './styles/globals.css';
 
 // Initialize Telegram WebApp (expand, disable swipes)
-initTelegramWebApp()
+initTelegramWebApp();
 
 // Preload logo from cache immediately on page load
-initLogoPreload()
+initLogoPreload();
 
 const queryClient = new QueryClient({
   defaultOptions: {
@@ -23,7 +23,7 @@ const queryClient = new QueryClient({
       refetchOnWindowFocus: false,
     },
   },
-})
+});
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
@@ -37,4 +37,4 @@ ReactDOM.createRoot(document.getElementById('root')!).render(
       </BrowserRouter>
     </QueryClientProvider>
   </React.StrictMode>,
-)
+);