feat: add authentication support and user model

- Updated `env.example` to include NextAuth configuration for authentication.
- Added `next-auth` dependency to manage user sessions.
- Introduced `User` model in Prisma schema with fields for user details and password hashing.
- Integrated `AuthProvider` in layout for session management across the app.
- Enhanced `Header` component with `AuthButton` for user authentication controls.

src/components/TowerLogo.tsx

@@ -0,0 +1,37 @@
+interface TowerLogoProps {
+  size?: 'sm' | 'md' | 'lg'
+  showText?: boolean
+  className?: string
+}
+
+export function TowerLogo({ size = 'md', showText = true, className = '' }: TowerLogoProps) {
+  const sizeClasses = {
+    sm: 'w-12 h-12',
+    md: 'w-20 h-20',
+    lg: 'w-32 h-32'
+  }
+
+  const textSizes = {
+    sm: 'text-2xl',
+    md: 'text-4xl',
+    lg: 'text-6xl'
+  }
+
+  return (
+    <div className={`text-center ${className}`}>
+      <div className={`inline-flex items-center justify-center ${sizeClasses[size]} rounded-2xl mb-4 text-6xl`}>
+        🗼
+      </div>
+      {showText && (
+        <>
+          <h1 className={`${textSizes[size]} font-mono font-bold text-[var(--foreground)] mb-2`}>
+            TowerControl
+          </h1>
+          <p className="text-[var(--muted-foreground)] text-lg">
+            Tour de contrôle de vos projets
+          </p>
+        </>
+      )}
+    </div>
+  )
+}