session-end

MUST use when user says 'bye', 'goodbye', 'good night', 'gnight', 'done for today', 'that's all', 'that's it', 'see you', 'see ya', 'let's stop', 'stopping here', 'wrapping up', 'signing off', 'closing down', 'done', 'finished for now', 'talk later', 'cya'. The user does NOT use slash commands; detect these natural session-ending phrases and run the full wrap-up automatically.