Live wall: report the starting view once so a copied link carries the viewport (#234)

Without it the URL had no z/lat/lon until the first pan, so a link copied
from an untouched wall opened at the other browser's remembered view.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-frontend/components/MapView.tsx

@@ -1274,6 +1274,10 @@ export default function MapView({
     mapInstance.on("overlayremove", onRemove);
     mapInstance.on("baselayerchange", onBase);
     mapInstance.on("moveend", onMove);
+    // Report the starting state once, so the URL carries the viewport even if
+    // the viewer never pans: a copied link must not fall back to the other
+    // browser's remembered view.
+    emit();
     return () => {
       clearTimeout(timer);
       mapInstance.off("overlayadd", onAdd);