783356852e
- Add keep_alive_interval and keep_alive_max_count to SshSecurityConfig - Enterprise default: 15s interval, 3 max failures - Development default: 30s interval, 5 max failures - Track last_activity timestamp in service loop - Send keepalive@openssh.com channel request when idle - Disconnect after max keepalive failures - Add build_keepalive_request() and get_first_session_channel() - Prevents connection timeout on idle SSH sessions All 229 tests pass.