feat: initialize Astro project with Tailwind and TypeScript

- Astro 5.0 with TypeScript strict mode
- Tailwind CSS 3.4 configured with custom design system
- Project structure created (components, layouts, content, styles)
- Sitemap and RSS integrations added
- Build verified successfully

Fixes dependency conflict by using Astro 5 instead of 6

tailwind.config.cjs

@@ -0,0 +1,29 @@
+module.exports = {
+  content: ['./src/**/*.{astro,html,js,jsx,md,mdx,ts,tsx}'],
+  darkMode: 'class',
+  theme: {
+    extend: {
+      colors: {
+        background: '#0a0e27',
+        surface: '#131729',
+        primary: '#60a5fa',
+        secondary: '#a78bfa',
+        text: {
+          primary: '#f1f5f9',
+          secondary: '#94a3b8',
+          tertiary: '#64748b',
+        },
+        accent: {
+          green: '#34d399',
+          red: '#f87171',
+          yellow: '#fbbf24',
+        }
+      },
+      fontFamily: {
+        sans: ['Inter', 'sans-serif'],
+        mono: ['JetBrains Mono', 'monospace'],
+      },
+    },
+  },
+  plugins: [require('@tailwindcss/typography')],
+};