Add LangChain/CrewAI integration example

[singularityjason]

Description

Create an example showing how to use Lightning Memory with popular agent frameworks like LangChain or CrewAI.

Acceptance Criteria

• Example script showing LangChain agent using Lightning Memory MCP tools
• OR: Example showing CrewAI agent with Lightning Memory
• README section or examples/ directory with the integration
• Working code that can be copy-pasted

Context

Lightning Memory works with any MCP-compatible agent, but having explicit integration examples with popular frameworks lowers the barrier to adoption.

This is a great first contribution — you just need familiarity with one of these frameworks.

[P-r-e-m-i-u-m]

Hi @singularityjason / @Gustav-Proxi, I would like to work on this issue. Could you please assign it to me?