♻️ 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/compiler/dist/shared/diagnostics.d.ts

@@ -1,18 +0,0 @@
-declare enum DiagnosticCode {
-    ERROR = 1000,
-    ERROR_UNTERMINATED_JS_COMMENT = 1001,
-    ERROR_FRAGMENT_SHORTHAND_ATTRS = 1002,
-    ERROR_UNMATCHED_IMPORT = 1003,
-    ERROR_UNSUPPORTED_SLOT_ATTRIBUTE = 1004,
-    WARNING = 2000,
-    WARNING_UNTERMINATED_HTML_COMMENT = 2001,
-    WARNING_UNCLOSED_HTML_TAG = 2002,
-    WARNING_DEPRECATED_DIRECTIVE = 2003,
-    WARNING_IGNORED_DIRECTIVE = 2004,
-    WARNING_UNSUPPORTED_EXPRESSION = 2005,
-    WARNING_SET_WITH_CHILDREN = 2006,
-    INFO = 3000,
-    HINT = 4000
-}
-
-export { DiagnosticCode };