Move the locate-me button into the top-left control stack

GeolocateControl was alone at bottom-right while Home/zoom/base-map were
grouped top-left — split across two corners instead of one stack like
the National Park Service's own map controls. Moved it in, between zoom
and the base-map button.

docs/architecture.adoc

@@ -141,15 +141,16 @@ sits top-left on the map, pinned to `CENTER`/`ZOOM` explicitly rather
 than its own fallback (the view at construction time, which would just
 be wherever a loaded permalink happened to point). It resets to the
 app's default view, not the visitor's own location — that's
-`GeolocateControl`, a separate button at bottom-right.
+`GeolocateControl`, a separate button in the same stack (below).
 
 That Home button is the top of a small top-left stack — Home, zoom
 in/out (`NavigationControl`, `showCompass: false` since this map never
-rotates), and a "Base map" button — matching the National Park
-Service's own map control layout (grouped together on the map itself,
-rather than split between the map and a side panel). The last of
-those, `MapLayersButton` (`public/js/map.js`), is a second entry point
-into the exact same Online/Offline panel `LayerToggleControl` already
+rotates), locate-me (`GeolocateControl`), and a "Base map" button —
+matching the National Park Service's own map control layout (grouped
+together on the map itself, rather than split across corners or
+between the map and a side panel). The last of those,
+`MapLayersButton` (`public/js/map.js`), is a second entry point into
+the exact same Online/Offline panel `LayerToggleControl` already
 manages in the page's own sidebar — both call the same
 `LayerToggleControl#toggle()`, so there's one source of truth for the
 panel's open/closed state either way.