Improve game initialization by ensuring the stage is visible before Pixi.js initialization; synchronize renderer on menu to game switch for better rendering performance.

src/TheLivingWorld.Web/src/main.ts

@@ -139,6 +139,9 @@ async function ensureMap(): Promise<void> {
 async function openWorld(id: string): Promise<void> {
   try {
     setStatus('Loading map…', 'busy');
+    // Stage must be visible before Pixi init / camera.fit — a hidden host measures as 0×0 and
+    // leaves the canvas stuck as a thin strip.
+    showGame();
     await ensureMap();
     const map = await api.getMap(id);
 
@@ -148,10 +151,10 @@ async function openWorld(id: string): Promise<void> {
     view.showWorld(map);
     elements.worldTitle.textContent = map.name;
     elements.hud.textContent = '';
-    showGame();
     setStatus('');
     await refreshWorldList();
   } catch (error) {
+    showMenu();
     setStatus(`Could not open world: ${message(error)}`, 'error');
   }
 }

src/TheLivingWorld.Web/src/map/mapView.ts

@@ -98,6 +98,9 @@ export class MapView {
     this.labels.clear();
     this.worldSizeMeters = map.sizeMeters;
 
+    // Host may have just become visible after a menu → game switch; sync the renderer before fitting.
+    this.app.resize();
+
     this.paintBackground();
     this.camera.fit(map.sizeMeters, this.viewport);
     this.chunks.setWorld(map.id, map.chunks);