2d71e9e9bc
A session key that exists in the store but would be rolled to a fresh session by the reset policy (daily/idle/suspended) is not an active session. Treating it as active suppressed the first-turn Slack thread-history reseed after reset (#55239). _has_active_session_for_thread() now consults SessionStore._should_reset so a stale entry gates like a missing one, letting _fetch_thread_context reseed the fresh session with recent thread history. Fixes #55239. Salvaged from #55240 by @ooiuuii.