Fix Stop permanently: navigate to real server path /game/{id} to force full page unload, add pathname routing to SPA

frontend/src/pages/Play.svelte

@@ -65,9 +65,9 @@
   }
 
   function stopEmulator() {
-    // Full page reload to guarantee all workers, AudioContexts,
-    // and WebAssembly threads are fully terminated
-    window.location.href = `/#/game/${game.id}`;
+    // Navigate to an actual server path to force full page unload
+    // which kills Web Workers, AudioContexts, and WASM threads
+    window.location.href = `/game/${game.id}`;
   }
 
   $effect(() => { load(); });