A zoom-8 reverse geocode of a UK place only resolves to the constituent
country (GB-ENG/SCT/WLS/NIR), but Natural Earth's admin-1 polygons for GB
are counties and boroughs (GB-LND, GB-MAN, GB-CON, ...). Those four codes
match no polygon, so places in England never highlighted in the Atlas
while CH/IT/NL/etc. worked. When a GB lookup lands on a constituent
country, re-resolve it at a finer zoom where Nominatim exposes the
county/borough code the polygons actually carry. Other countries keep the
exact zoom-8 behaviour. Adds ATLAS-UNIT-021.
trek_photos is now the central registry; trip_photos and journey_photos
reference it via photo_id FK. Updated all affected test helpers and
direct-SQL assertions to join trek_photos instead of querying stale
columns (asset_id, provider, owner_id) on the leaf tables.
Also fix ATLAS-UNIT-019: getVisitedRegions now fires background geocoding
and returns immediately, so the test must call it twice — once to trigger
the fill, once after advancing fake timers to read cached results.