Animated NPCs and Maya's first walk cycle

Animated friendly NPCs are finally a thing. Triggers in walking scenes can now carry a small animation set, and auri is the pilot — three idle poses cycling, plus a welcome reaction. The animation system is data-driven, so adding a new animated character is going to be a content drop rather than custom wiring each time.

Maya gets her first walking-scene animations the same day: a 3-frame side idle and a side walk cycle. Walking scenes now show Maya actually walking instead of gliding her front-facing sprite across the floor — small thing but it changes how alive the hubs feel. The hub animations (auri's idles + welcome and Maya's new ones) all moved over to sprite sheets at the same time. Sprite sheets pack a character's frames into one image, which means fewer files for the device to load and noticeably smaller download size — auri's assets dropped about 25%, and Maya's idles and walk live in two sheets total.