♻️ 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)

dealplustech-astro/node_modules/prismjs/components/prism-hpkp.js

@@ -1,14 +0,0 @@
-/**
- * Original by Scott Helme.
- *
- * Reference: https://scotthelme.co.uk/hpkp-cheat-sheet/
- */
-
-Prism.languages.hpkp = {
-	'directive': {
-		pattern: /\b(?:includeSubDomains|max-age|pin-sha256|preload|report-to|report-uri|strict)(?=[\s;=]|$)/i,
-		alias: 'property'
-	},
-	'operator': /=/,
-	'punctuation': /;/
-};