feat(schema): Added multi-field indexes to LiteLLM_SpendLogs to improve query performance

- Added indexes to the user, status, api_key, user+startTime, and model_group fields for the LiteLLM_SpendLogs model

- Optimized query efficiency for related fields, improving data retrieval performance

schema.prisma

@@ -504,6 +504,11 @@ model LiteLLM_SpendLogs {
   mcp_namespaced_tool_name String? 
   agent_id            String?
   proxy_server_request Json?     @default("{}")
+  @@index([user])
+  @@index([status])
+  @@index([api_key])
+  @@index([user, startTime])
+  @@index([model_group])
   @@index([startTime])
   @@index([end_user])
   @@index([session_id])