Refactor LambdaAgent to use OpenAI client and update cost manager with new Lambda model expenses

LambdaAgent added

Updated expense model

Refactor GroqAgent initialization and enhance error handling; update AgentCostManager with Groq model costs

updated costs

include cost per 1000 tokes

Implemented mode selection

Add GroqAgent and GroqModelManager implementations for Groq model integration

Add support for deepseek-r1 model in AgentManager and AgentCostManager

Added expense budget

Giving agent access to the model costs

Fixing tool deletion

refactor