fix(web): prevent stopGame from being called on non-game page transitions

Only stop the game when navigating away from the game page (/) to avoid
WASM runtime errors when navigating between /leaderboard and /download.
Add error handling to gracefully handle crashes during page transitions.

web/pages/+onPageTransitionEnd.ts

@@ -23,7 +23,11 @@ function restartGame() {
   const win = getPacmanWindow();
   const module = win.Module;
 
-  if (module?._restart_game) {
+  if (!module?._restart_game) {
+    console.warn("Game restart function not available (WASM may not be initialized)");
+    return;
+  }
+
   const canvas = document.getElementById("canvas") as HTMLCanvasElement | null;
   if (!canvas) {
     console.error("Canvas element not found during game restart");
@@ -41,5 +45,4 @@ function restartGame() {
   } catch (error) {
     console.error("Failed to restart game:", error);
   }
-  }
 }

web/pages/+onPageTransitionStart.ts

@@ -10,11 +10,18 @@ export const onPageTransitionStart: OnPageTransitionStartAsync = async (pageCont
   setPendingNavigation(pageContext.urlPathname);
   document.querySelector("body")?.classList.add("page-is-transitioning");
 
-  // Stop the game loop when navigating away from the game page
+  // Only stop the game when navigating AWAY FROM the game page
+  // Don't stop when navigating between other pages (e.g., /leaderboard <-> /download)
+  if (window.location.pathname === "/") {
     const win = getPacmanWindow();
     if (win.Module?._stop_game) {
+      try {
         console.log("Stopping game loop for page transition");
         win.Module._stop_game();
+      } catch (error) {
+        console.warn("Failed to stop game (game may have already crashed):", error);
+      }
+    }
   }
 
   // Wait for fade-out animation to complete before page content changes