fix(router): use query param instead of hash for anchor scrolling

HashRouter already uses # for routing, so we can't use hash anchors.
Use ?scrollTo=assembly-video query param instead.
Example: /#/getting-started?scrollTo=assembly-video

src/App.jsx

@@ -16,20 +16,23 @@ function ScrollToTop() {
   const location = useLocation();
 
   useEffect(() => {
-    // Si il y a un hash (ancre), scroll vers cet élément
-    if (location.hash) {
-      // Petit délai pour laisser le DOM se charger
+    // Check for scrollTo query parameter (used for anchor-like behavior with HashRouter)
+    const params = new URLSearchParams(location.search);
+    const scrollTo = params.get('scrollTo');
+    
+    if (scrollTo) {
+      // Small delay to let the DOM render
       setTimeout(() => {
-        const element = document.getElementById(location.hash.slice(1));
+        const element = document.getElementById(scrollTo);
         if (element) {
           element.scrollIntoView({ behavior: 'smooth', block: 'center' });
         }
       }, 100);
     } else {
-      // Sinon, scroll en haut de la page
+      // Otherwise scroll to top
       window.scrollTo({ top: 0, behavior: 'smooth' });
     }
-  }, [location.pathname, location.hash]);
+  }, [location.pathname, location.search]);
 
   return null;
 }