Marketplace Offers Router Enhancement:
✅ NEW ENDPOINT: GET /offers for listing all marketplace offers
- Added fixed version to avoid AttributeError from GlobalMarketplaceService
- Uses direct database query with SQLModel select
- Safely extracts offer attributes with fallback defaults
- Returns structured offer data with GPU specs and metadata
✅ ENDPOINT FEATURES:
🔧 Direct Query: Bypasses service layer to avoid attribute
