♻️ 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/vite/dist/client/env.mjs

@@ -1,24 +0,0 @@
-const context = (() => {
-  if (typeof globalThis !== "undefined") {
-    return globalThis;
-  } else if (typeof self !== "undefined") {
-    return self;
-  } else if (typeof window !== "undefined") {
-    return window;
-  } else {
-    return Function("return this")();
-  }
-})();
-const defines = __DEFINES__;
-Object.keys(defines).forEach((key) => {
-  const segments = key.split(".");
-  let target = context;
-  for (let i = 0; i < segments.length; i++) {
-    const segment = segments[i];
-    if (i === segments.length - 1) {
-      target[segment] = defines[key];
-    } else {
-      target = target[segment] || (target[segment] = {});
-    }
-  }
-});