Replaced inner-sidebar layout (which collided with the generic app
sidebar) with a Meshtastic-style top connection strip + body row.
Contacts/nodes panel sits left of the tabbed content area, matching
the established pattern. Map now uses Settings.createTileLayer() with
a dark CartoDB fallback instead of plain OSM light tiles.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>