♻️ 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-go-module.min.js

@@ -1 +0,0 @@
-Prism.languages["go-mod"]=Prism.languages["go-module"]={comment:{pattern:/\/\/.*/,greedy:!0},version:{pattern:/(^|[\s()[\],])v\d+\.\d+\.\d+(?:[+-][-+.\w]*)?(?![^\s()[\],])/,lookbehind:!0,alias:"number"},"go-version":{pattern:/((?:^|\s)go\s+)\d+(?:\.\d+){1,2}/,lookbehind:!0,alias:"number"},keyword:{pattern:/^([ \t]*)(?:exclude|go|module|replace|require|retract)\b/m,lookbehind:!0},operator:/=>/,punctuation:/[()[\],]/};