refactor: Move Astro project to root directory

- Move all Astro files from dealplustech-astro/ to root
- Archive Next.js code in _nextjs-backup/
- Update .gitignore for Astro project
- Simplify project structure

This completes the migration from Next.js to Astro.
The Astro project is now at the root level.

.gitignore

@@ -1,39 +1,48 @@
-# dependencies
-/node_modules
-/.pnp
+# Dependencies
+node_modules/
+.pnp
 .pnp.js
-.yarn/install-state.gz
 
-# testing
-/coverage
+# Testing
+coverage/
 
-# next.js
-/.next/
-/out/
+# Next.js (backup only)
+_nextjs-backup/
 
-# production
-/build
+# Astro
+.astro/
 
-# misc
+# Build
+dist/
+build/
+
+# Production
+*.local
+
+# Editor
+.vscode/*
+!.vscode/extensions.json
+.idea/
 .DS_Store
-*.pem
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
 
-# debug
+# Logs
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
 
-# local env files
-.env*.local
+# Uploads
+./upload/*
+
+# Misc
 .env
-
-# vercel
-.vercel
-
-# typescript
-*.tsbuildinfo
-next-env.d.ts
-
-# IDE
-.idea/
-.vscode/
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local