Story map: pinch zoom, hidden quest paths, no more overlapping nodes

The story map is now pinch-zoomable on mobile, from half size to one-and-a-half. Scroll wheel does the same on web. The point under your fingers stays anchored as you zoom, so you don't lose your place. Auto-scroll-to-last-opened-node still runs on first layout, but once you've zoomed manually it stops pulling the view away from you.

Quest scenes and their descendants are now hidden on the map until you've actually taken the quest. Before, the map drew every quest path whether or not you'd talked to the giver — which spoiled what was coming. Take the quest from the merchant and the path appears with the Q marker.

Scene nodes no longer overlap each other. The overlap pass used to assume every name fits on one line, but long names wrap to two — pushing the real bounding box past the assumed one and causing collisions. The math accounts for wrap now, and a post-layout pass resolves any pairs that still end up too close.