Refactor payment service, fix DB session, and consolidate endpoints

- Fix critical NameError in database.py by restoring Session factory
- Refactor payment_service.py and crud.py to use shared constants.py and utils.py
- Deduplicate state mapping and input sanitization logic
- Move transaction amount calculation logic from CRUD to Router layer
- Enforce type safety in schemas using IntEnum for TransactionType/Status
- Move capture endpoint from transaction.py to payment.py (now /payments/capture)
- Update create_customer_profile signature for clarity

app/database.py

@@ -25,11 +25,10 @@ engine = create_engine(
     pool_recycle=3600,       # Recycle connections after 1 hour
 )
 
-Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)
-session = Session()
-
 Base = declarative_base()
-Base.metadata.create_all(engine)
+
+
+Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 
 
 def get_db():