Don't start zoomed in on SanFrancisco

mappers.helium.com defaults to a zoomed in view, whereas explorer defaults to a zoomed out view.

The zoomed in view is very tedious to zoom out then back in (especially on mobile)

Change the default view of mappers to be zoomed out (or better yet make it detect my current location)

Start by locating where mappers.helium.com sets the map's initial view, then compare its default with the explorer's zoomed-out view. Verify on desktop and mobile that the mapper opens zoomed out; current-location detection is an optional alternative, not a defined requirement.

Written by the indexing model from the issue text.