How do chests and keys work?

Chests are earned from big orders and chapter finales — they are never sold and never cost money. A chest sits on your board taking one cell until you open it; keys wait in your Planner's Kit. Tap the chest to see which key it needs, then confirm to open. Rewards wait for you to claim — nothing is auto-claimed or lost. Keys merge like everything else: two Bronze make a Silver, two Silver make a Gold. Open small chests now, or save toward a Gold — your call. Both are good.