Nilo Timer

- Wind-up and wind-down phases. A timer can have an optional lead-in before its first round and an optional cool-down after its last. Both are off by default and switched on in the editor, with presets or a stepper for the length. A new start sound fires when the wind-up hands over to the first round, including from the background. - Timer chains. A chain button turns the timer list into an ordered picker. Tap order is run order, and the picked timers run back to back as a single run. Background notifications name each timer in the chain, and an open run view follows the chain instead of being orphaned. - Storage schema v2. The two new timer fields are additive, so existing timers migrate without change. - All eight languages got strings for the new editor controls and run states.