[Feature Request] Sliding session lifetime (idle timeout instead of absolute timeout)

[sgaluza]

Summary

Currently, the session lifetime feature (added in PR #175) uses an absolute timeout from session creation time. This means a session will be terminated after the configured duration regardless of whether it's actively being used.

Current behavior:

• Session created at 10:00
• Lifetime = 30 minutes
• Session terminated at 10:30, even if actively used at 10:29

Proposed behavior (sliding/idle timeout):

• Session created at 10:00
• Lifetime = 30 minutes (idle timeout)
• Each request resets the timer
• If last request was at 10:25, session terminates at 10:55

Use Case

When using MetaMCP with AI coding assistants (Claude Code, Cursor, GitHub Copilot, etc.), sessions can be long-lived with intermittent activity. The current absolute timeout forces session recreation during active work sessions, which:

1. Interrupts ongoing work
2. Requires clients to handle session expiration and reconnection
3. May cause tool state loss in stateful MCP servers

A sliding/idle timeout would only terminate truly inactive sessions while keeping active ones alive.

Question

Does this approach make sense for MetaMCP? I'd be happy to submit a PR if this feature aligns with the project's goals.

Related Issues

• [Bug/Question] Connection Timeout (5 mins) in LAN via Kilo Code - Missing Heartbeat mechanism? #215 - Connection Timeout (related to keep-alive, different issue)
• Expired sessions don't appear to be handled according to spec #166 - Expired sessions handling (related to reconnection logic)