Game state and loop

Model the game as a small explicit state machine with one owner of the clock. Every transition names its states; behaviour, input, and the interface read the current state rather than a scatter of booleans.

States and transitions

• Enumerate the states — for example ready, playing, paused, over — and make transitions explicit and total. Do not infer state from side effects.
• Gate the simulation on the active state: advance gameplay, timers, and physics only while playing.

Capture input and pause