chore: complete initial setup for Next.js project with TypeScript, Tailwind CSS, ESLint, and Prettier; remove unnecessary .DS_Store file

src/components/layout/Header.tsx

@@ -0,0 +1,37 @@
+'use client';
+
+import Link from 'next/link';
+import { useTheme } from '@/contexts/ThemeContext';
+
+export function Header() {
+  const { theme, toggleTheme } = useTheme();
+
+  return (
+    <header className="sticky top-0 z-50 border-b border-border bg-card/80 backdrop-blur-sm">
+      <div className="mx-auto flex h-16 max-w-7xl items-center justify-between px-4">
+        <Link href="/" className="flex items-center gap-2">
+          <span className="text-2xl">📊</span>
+          <span className="text-xl font-bold text-foreground">SWOT Manager</span>
+        </Link>
+
+        <nav className="flex items-center gap-4">
+          <Link
+            href="/sessions"
+            className="text-muted transition-colors hover:text-foreground"
+          >
+            Mes Sessions
+          </Link>
+
+          <button
+            onClick={toggleTheme}
+            className="flex h-9 w-9 items-center justify-center rounded-lg border border-border bg-card text-lg transition-colors hover:bg-card-hover"
+            aria-label="Toggle theme"
+          >
+            {theme === 'light' ? '🌙' : '☀️'}
+          </button>
+        </nav>
+      </div>
+    </header>
+  );
+}
+