The Locations Sites tab for the phoenix_kit_projects hub — this
module's phoenix_kit_project_extensions/0 contribution (see that
function in PhoenixKitLocations).
Rendered by the projects hub via live_render with its embed-session
contract; linkage is CONFIG-based (location_uuids, comma-separated in
the project's Modules panel) — no FK, no dependency on the projects
package. Read-only address cards with link-outs to the locations admin.
Off-router-mountable: no handle_params/3 (the hub's hard requirement).