♻️ 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/mdast-util-to-markdown/lib/join.js

@@ -1,39 +0,0 @@
-/**
- * @import {Join} from 'mdast-util-to-markdown'
- */
-
-import {formatCodeAsIndented} from './util/format-code-as-indented.js'
-import {formatHeadingAsSetext} from './util/format-heading-as-setext.js'
-
-/** @type {Array<Join>} */
-export const join = [joinDefaults]
-
-/** @type {Join} */
-function joinDefaults(left, right, parent, state) {
-  // Indented code after list or another indented code.
-  if (
-    right.type === 'code' &&
-    formatCodeAsIndented(right, state) &&
-    (left.type === 'list' ||
-      (left.type === right.type && formatCodeAsIndented(left, state)))
-  ) {
-    return false
-  }
-
-  // Join children of a list or an item.
-  // In which case, `parent` has a `spread` field.
-  if ('spread' in parent && typeof parent.spread === 'boolean') {
-    if (
-      left.type === 'paragraph' &&
-      // Two paragraphs.
-      (left.type === right.type ||
-        right.type === 'definition' ||
-        // Paragraph followed by a setext heading.
-        (right.type === 'heading' && formatHeadingAsSetext(right, state)))
-    ) {
-      return
-    }
-
-    return parent.spread ? 1 : 0
-  }
-}