Featurefix: resolve product image loading and admin product management issues

[vishnu-R2005]

Summary

This PR fixes product image handling across the GoCart application and improves the admin product management workflow.

Changes Made

Product Images

• Fixed product images not displaying on Home and Products pages
• Added support for both relative and absolute media URLs
• Improved image rendering in ProductCard component
• Fixed image upload flow for newly created products
• Fixed image updates when editing products

Admin Product Management

• Improved Add Product page functionality
• Improved Edit Product page functionality
• Fixed product creation response handling
• Added support for updating product images from the admin panel

Admin Experience

• Simplified admin navigation
• Admin users now see only:
  • Admin Dashboard
  • Logout

Testing

• Verified product creation
• Verified product editing
• Verified image uploads
• Verified image updates
• Verified image display on Home page
• Verified image display on Products page
• Verified admin dashboard access
• Verified admin navigation behavior

Impact

• Better admin product management workflow
• Correct image rendering across the application
• Improved overall user experience