refactor: add aitbc package to Python path in marketplace-service

- Added sys and pathlib imports to main.py
- Inserted parent directory (5 levels up) to sys.path for aitbc package resolution
- Ensures marketplace-service can import shared aitbc modules

apps/marketplace-service/src/marketplace_service/main.py

@@ -3,6 +3,11 @@ Marketplace Service main application
 Manages GPU marketplace operations
 """
 
+import sys
+from pathlib import Path
+# Add aitbc package to Python path
+sys.path.insert(0, str(Path(__file__).parent.parent.parent.parent.parent))
+
 from contextlib import asynccontextmanager
 from typing import AsyncIterator