♻️ 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/astro/dist/template/4xx.d.ts

@@ -1,18 +0,0 @@
-interface ErrorTemplateOptions {
-    /** a short description of the error */
-    pathname: string;
-    /** HTTP error code */
-    statusCode?: number;
-    /** HTML <title> */
-    tabTitle: string;
-    /** page title */
-    title: string;
-    /** The body of the message, if one is provided */
-    body?: string;
-}
-/** Display all errors */
-export default function template({ title, pathname, statusCode, tabTitle, body, }: ErrorTemplateOptions): string;
-export declare function subpathNotUsedTemplate(base: string, pathname: string): string;
-export declare function trailingSlashMismatchTemplate(pathname: string, trailingSlash: 'always' | 'never' | 'ignore'): string;
-export declare function notFoundTemplate(pathname: string, message?: string): string;
-export {};