CameraFollowPolicy

One rule for every AUTOMATIC "move the camera to the user" path (#289).

When the app has selected a venue (or asked for one to be plotted) and the user is not inside it, an automatic camera move to the user would carry the camera away from that venue and leave an empty map. That happened when the first GPS fix arrived after the venue was plotted: the launch recenter and the per-fix follow both moved the camera to a phone thousands of km away.

Explicit user actions (recenter button, Go, Navigate) are NOT subject to this rule; they mean "show me where I am".

Two selections are considered, because they change at different times: the core selection is set as soon as the app asks for a venue, the map's selection only after the plot finishes. A user counts as inside only when their venue id is a real id (> 0) equal to one of them; the "outside every venue" value -1 never matches a selection of -1. With no venue selected anywhere, following the user is allowed.