[Pharex38]

In the v2 API a transition is sent as dynamics.duration (milliseconds), for example PUT /clip/v2/resource/light/<id> with {"on": {"on": true}, "dynamics": {"duration": 4000}}. v2StateToV1 only looked at the non-standard top-level transitiontime, so the duration was dropped and every v2 change ran with the protocol's default transition.

v2StateToV1 now converts dynamics.duration to v1 transitiontime (100 ms steps). Light PUTs (Light.setV2State) and grouped_light PUTs (setV2Action) both go through it, so both get the transition. From there it takes the same path as a v1 request with transitiontime. dynamics.speed (effect speed) is still handled in Light.setV2State as before, and the old top-level transitiontime still wins if a client sends it.

Tests: tests/test_v2_state_conversion.py covers the duration conversion, rounding, and that speed alone sets no transition. The duration cases fail on master; pytest tests passes.