♻️ 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/@astrojs/markdown-remark/dist/rehype-shiki.js

@@ -1,29 +0,0 @@
-import { highlightCodeBlocks } from "./highlight.js";
-import { createShikiHighlighter } from "./shiki.js";
-const rehypeShiki = (config, excludeLangs) => {
-  let highlighterAsync;
-  return async (tree) => {
-    highlighterAsync ??= createShikiHighlighter({
-      langs: config?.langs,
-      theme: config?.theme,
-      themes: config?.themes,
-      langAlias: config?.langAlias
-    });
-    const highlighter = await highlighterAsync;
-    await highlightCodeBlocks(
-      tree,
-      (code, language, options) => {
-        return highlighter.codeToHast(code, language, {
-          meta: options?.meta,
-          wrap: config?.wrap,
-          defaultColor: config?.defaultColor,
-          transformers: config?.transformers
-        });
-      },
-      excludeLangs
-    );
-  };
-};
-export {
-  rehypeShiki
-};