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/vite-env.d.ts

@@ -1,91 +1,94 @@
 /// <reference types="vite/client" />
 
 interface ImportMetaEnv {
-  readonly VITE_API_URL: string
-  readonly VITE_TELEGRAM_BOT_USERNAME?: string
-  readonly VITE_APP_NAME?: string
-  readonly VITE_APP_LOGO?: string
+  readonly VITE_API_URL: string;
+  readonly VITE_TELEGRAM_BOT_USERNAME?: string;
+  readonly VITE_APP_NAME?: string;
+  readonly VITE_APP_LOGO?: string;
 }
 
 interface ImportMeta {
-  readonly env: ImportMetaEnv
+  readonly env: ImportMetaEnv;
 }
 
 // Telegram WebApp types
 interface TelegramWebApp {
-  initData: string
+  initData: string;
   initDataUnsafe: {
     user?: {
-      id: number
-      first_name: string
-      last_name?: string
-      username?: string
-      language_code?: string
-    }
-    auth_date: number
-    hash: string
-  }
-  version: string
-  platform: string
-  isExpanded: boolean
-  isClosingConfirmationEnabled: boolean
-  isVerticalSwipesEnabled: boolean
-  isFullscreen: boolean
-  isOrientationLocked: boolean
-  safeAreaInset: { top: number; bottom: number; left: number; right: number }
-  contentSafeAreaInset: { top: number; bottom: number; left: number; right: number }
-  ready: () => void
-  expand: () => void
-  close: () => void
-  openLink: (url: string, options?: { try_instant_view?: boolean; try_browser?: boolean }) => void
-  openTelegramLink: (url: string) => void
-  openInvoice: (url: string, callback?: (status: 'paid' | 'cancelled' | 'failed' | 'pending') => void) => void
+      id: number;
+      first_name: string;
+      last_name?: string;
+      username?: string;
+      language_code?: string;
+    };
+    auth_date: number;
+    hash: string;
+  };
+  version: string;
+  platform: string;
+  isExpanded: boolean;
+  isClosingConfirmationEnabled: boolean;
+  isVerticalSwipesEnabled: boolean;
+  isFullscreen: boolean;
+  isOrientationLocked: boolean;
+  safeAreaInset: { top: number; bottom: number; left: number; right: number };
+  contentSafeAreaInset: { top: number; bottom: number; left: number; right: number };
+  ready: () => void;
+  expand: () => void;
+  close: () => void;
+  openLink: (url: string, options?: { try_instant_view?: boolean; try_browser?: boolean }) => void;
+  openTelegramLink: (url: string) => void;
+  openInvoice: (
+    url: string,
+    callback?: (status: 'paid' | 'cancelled' | 'failed' | 'pending') => void,
+  ) => void;
   // Fullscreen API (Bot API 8.0+)
-  requestFullscreen: () => void
-  exitFullscreen: () => void
-  lockOrientation: () => void
-  unlockOrientation: () => void
+  requestFullscreen: () => void;
+  exitFullscreen: () => void;
+  lockOrientation: () => void;
+  unlockOrientation: () => void;
   // Vertical swipes control
-  disableVerticalSwipes: () => void
-  enableVerticalSwipes: () => void
+  disableVerticalSwipes: () => void;
+  enableVerticalSwipes: () => void;
   // Closing confirmation
-  enableClosingConfirmation: () => void
-  disableClosingConfirmation: () => void
+  enableClosingConfirmation: () => void;
+  disableClosingConfirmation: () => void;
   // Event handlers
-  onEvent: (eventType: string, callback: () => void) => void
-  offEvent: (eventType: string, callback: () => void) => void
+  onEvent: (eventType: string, callback: () => void) => void;
+  offEvent: (eventType: string, callback: () => void) => void;
   MainButton: {
-    text: string
-    color: string
-    textColor: string
-    isVisible: boolean
-    isActive: boolean
-    show: () => void
-    hide: () => void
-    enable: () => void
-    disable: () => void
-    onClick: (callback: () => void) => void
-    offClick: (callback: () => void) => void
-  }
+    text: string;
+    color: string;
+    textColor: string;
+    isVisible: boolean;
+    isActive: boolean;
+    show: () => void;
+    hide: () => void;
+    enable: () => void;
+    disable: () => void;
+    onClick: (callback: () => void) => void;
+    offClick: (callback: () => void) => void;
+  };
   BackButton: {
-    isVisible: boolean
-    show: () => void
-    hide: () => void
-    onClick: (callback: () => void) => void
-    offClick: (callback: () => void) => void
-  }
+    isVisible: boolean;
+    show: () => void;
+    hide: () => void;
+    onClick: (callback: () => void) => void;
+    offClick: (callback: () => void) => void;
+  };
   themeParams: {
-    bg_color?: string
-    text_color?: string
-    hint_color?: string
-    link_color?: string
-    button_color?: string
-    button_text_color?: string
-  }
+    bg_color?: string;
+    text_color?: string;
+    hint_color?: string;
+    link_color?: string;
+    button_color?: string;
+    button_text_color?: string;
+  };
 }
 
 interface Window {
   Telegram?: {
-    WebApp: TelegramWebApp
-  }
+    WebApp: TelegramWebApp;
+  };
 }