Initial project setup: monorepo structure with frontend and backend

- Set up pnpm workspace with frontend (React + Vite) and backend (Express + Prisma)
- Configure TypeScript, ESLint, and Prettier
- Add Prisma schema for database models (User, Course, Lesson, Progress, etc.)
- Create basic frontend structure with Tailwind CSS and shadcn/ui
- Add environment configuration files
- Update README with project overview and setup instructions
- Complete Phase 0: Project initialization

packages/backend/.eslintrc.cjs

@@ -0,0 +1,18 @@
+module.exports = {
+  root: true,
+  env: { node: true, es2020: true },
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+  ],
+  ignorePatterns: ['dist', '.eslintrc.cjs'],
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    ecmaVersion: 'latest',
+    sourceType: 'module',
+  },
+  rules: {
+    '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
+  },
+};
+