feat: recover portfolio pages from scratch workspaces

- Add base layouts (BaseLayout, BlogLayout, ProjectLayout)
- Add UI components (Header, Footer, Navigation, Card, Tag)
- Add About page with personal story
- Add Projects pages (index, detail)
- Add homepage content
- Add SEO files (robots.txt, webmanifest)

Work was done by agents in isolated workspaces.
Consolidated into main repo for proper git tracking.

src/components/layout/Navigation.astro

@@ -0,0 +1,24 @@
+---
+const navItems = [
+  { href: '/about', label: 'Sobre mí' },
+  { href: '/projects', label: 'Proyectos' },
+  { href: '/blog', label: 'Blog' },
+];
+
+const currentPath = Astro.url.pathname;
+---
+
+<nav class="flex items-center gap-6">
+  {navItems.map(item => (
+    <a 
+      href={item.href}
+      class={`text-sm font-medium transition-colors hover:text-primary ${
+        currentPath.startsWith(item.href) 
+          ? 'text-primary' 
+          : 'text-text-secondary'
+      }`}
+    >
+      {item.label}
+    </a>
+  ))}
+</nav>