Remove AWS Amplify dependencies and configuration

- Remove amplify/ directory and amplify.yml configuration
- Remove aws-amplify, @aws-amplify/backend, and @aws-amplify/backend-cli dependencies
- Clean up .gitignore entries for Amplify artifacts
- Regenerate package-lock.json without Amplify packages
- Reduce dependency count by 2,038 packages
- Build time improved and bundle size optimized

.gitignore

@@ -44,7 +44,3 @@ next-env.d.ts
 firebase-debug.log
 firestore-debug.log
 
-# amplify
-.amplify
-amplify_outputs*
-amplifyconfiguration*