fix #32 wrong use of lower()

Author: jexp

servers/mcp-neo4j-cloud-aura-api/src/mcp_neo4j_aura_manager/server.py

@@ -192,10 +192,10 @@ def create_instance(self, tenant_id: str, name: str, memory: int = 1, region: st
 
         # Add optional parameters only if they're provided and applicable            
         if graph_analytics_plugin and type in ["professional-db", "enterprise-db", "business-critical"]:
-            payload["graph_analytics_plugin"] = lower(str(graph_analytics_plugin))
+            payload["graph_analytics_plugin"] = str(graph_analytics_plugin).lower()
 
         if vector_optimized and type in ["professional-db", "enterprise-db", "business-critical"]:
-            payload["vector_optimized"] = lower(str(vector_optimized))
+            payload["vector_optimized"] = str(vector_optimized).lower()
 
         if source_instance_id and type in ["professional-db", "enterprise-db", "business-critical"]:
             payload["source_instance_id"] = source_instance_id
@@ -216,7 +216,7 @@ def update_instance(self, instance_id: str, name: Optional[str] = None,
         if memory is not None:
             payload["memory"] = f"{memory}GB"
         if vector_optimized is not None:
-            payload["vector_optimized"] = lower(str(vector_optimized))
+            payload["vector_optimized"] = str(vector_optimized).lower()
 
         print("Update instance payload:")
         print(payload)