♻️ Restructure: Move Astro to repository root

BREAKING CHANGE: Astro project is now at repository root
- Removed dealplustech-astro subdirectory
- Moved all Astro files to root
- Updated PostCSS config to .cjs
- Removed old Next.js files

✅ 11 pages built successfully
✅ Cookie consent banner included
✅ Privacy/Terms links in footer
✅ Ready for Easypanel deployment (no root dir needed)

Migration path:
- Old structure: /dealplustech-astro/
- New structure: / (root)

astro.config.mjs

@@ -0,0 +1,9 @@
+import { defineConfig } from 'astro/config';
+import tailwindcss from '@tailwindcss/vite';
+
+export default defineConfig({
+  vite: {
+    plugins: [tailwindcss()]
+  },
+  output: 'static'
+});