♻️ 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
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✅ 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/rehype-stringify/lib/index.js

@@ -1,31 +0,0 @@
-/**
- * @import {Root} from 'hast'
- * @import {Options} from 'hast-util-to-html'
- * @import {Compiler, Processor} from 'unified'
- */
-
-import {toHtml} from 'hast-util-to-html'
-
-/**
- * Plugin to add support for serializing as HTML.
- *
- * @param {Options | null | undefined} [options]
- *   Configuration (optional).
- * @returns {undefined}
- *   Nothing.
- */
-export default function rehypeStringify(options) {
-  /** @type {Processor<undefined, undefined, undefined, Root, string>} */
-  // @ts-expect-error: TS in JSDoc generates wrong types if `this` is typed regularly.
-  const self = this
-  const settings = {...self.data('settings'), ...options}
-
-  self.compiler = compiler
-
-  /**
-   * @type {Compiler<Root, string>}
-   */
-  function compiler(tree) {
-    return toHtml(tree, settings)
-  }
-}