Fix missing useEffect dependencies in ProviderMap MarkerLayer

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/organisms/ProviderMap/ProviderMap.tsx

@@ -288,7 +288,7 @@ const MarkerLayer: React.FC<{
         roots.forEach((r) => r.unmount());
       }, 0);
     };
-  }, [map, markerLibrary, providers, hiddenIds]);
+  }, [map, markerLibrary, providers, hiddenIds, externalisePopups, theme]);
 
   return null;
 };