Add session timeouts

[srikanthramu]

Is your feature request related to a problem? Please describe.

Add session timeouts for Session ID (Mcp-Session-Id). Session Hijacking mitigations suggests session expiry to reduce session hijacking issues, this is currently unimplemented in the Ruby SDK.

Describe the solution you'd like
Please refer similar implementations in other SDKs:
go-sdk

• https://github.com/modelcontextprotocol/go-sdk/blob/main/mcp/streamable.go#L526-L530

csharp-sdk

• https://github.com/modelcontextprotocol/csharp-sdk/blob/main/src/ModelContextProtocol.AspNetCore/HttpServerTransportOptions.cs#L110-L138