- hand sweeps down the button panel at game start
- button panel now spawns its floor buttons procedurally via button_panel.gd
- elevator_panel waits for the new intro_finished signal before starting floor 1
- removes the stray ShaftStrip from hud.tscn
- cleaned up timing but henry will probably want to tune further
- Move elevator panel logic out of HUD; HUD now listens for signals to update floor, saved, people, and score labels
- Add scaling rescue threshold that grows as you descend, with bonus points for exceeding it
- Add per-floor timer that triggers a losing when expired
- Add show_loss state on the screen for too-few-people and timeout failures
