Keep the map's zoom floor inside MapLibre's range

At Leaflet zoom 0 the adapter drives the MapLibre map to -1, below the
range MapLibre is specified for. Measured, no drift was observable there
and the centres stayed in sync, but the adapter's own README recommends a
floor of 1 and nobody views a home automation dashboard from world zoom,
so there is nothing to weigh against staying inside spec.

Spotted in #53836 by @birkskyum, which set this correctly where this
branch did not.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: bramkragten

src/common/map/base-layer.ts

@@ -36,7 +36,12 @@ const CONTEXT_RESTORE_GRACE = 2000;
 // The zoom range belongs to the map rather than to the base layer: only Leaflet
 // tile layers report their own limits, and marker clustering needs the map to
 // have a maximum zoom whichever base layer is in use.
-export const MAP_MIN_ZOOM = 0;
+//
+// The floor is 1 rather than 0 on the adapter's own advice: at Leaflet zoom 0 it
+// drives the MapLibre map to -1, below the range MapLibre is specified for. No
+// drift was measurable there, but nobody looks at their house from world zoom,
+// so there is nothing to weigh against staying inside spec.
+export const MAP_MIN_ZOOM = 1;
 export const MAP_MAX_ZOOM = 20;
 
 export interface MapBaseLayer {