The launcher (hermes_cli/main.py _print_tui_exit_summary) reads
HERMES_TUI_ACTIVE_SESSION_FILE to print 'Resume this session with…' on exit. The
Ink TUI writes the current session id there on every session change
(useSessionLifecycle.writeActiveSessionFile); the native engine never did, so
after a /session switch the launcher fell back to the INITIAL launch session and
showed resume info for the wrong session (the reported leak).
Now writeActiveSession() writes {session_id} on session.create AND inside
resumeInto (every /session switch), mirroring Ink. Verified live: file shows the
created session, then updates to the switched-to session. 85 pass.