fix(studio): prevent route transition DOM duplication via AnimatePresence (#4987)

Add mode="wait" and exit={{ opacity: 0 }} to the root AnimatePresence
wrapper so outgoing routes fully unmount before incoming routes render.
Without this, rapid navigation between Studio/Export/Recipes/Chat caused
pages to stack (2x–3x duplication).

Co-authored-by: AdamPlatin123 <AdamPlatin123@users.noreply.github.com>
Co-authored-by: Wasim Yousef Said <wasimysdev@gmail.com>

studio/frontend/src/app/routes/__root.tsx

@@ -40,11 +40,12 @@ function RootLayout() {
   return (
     <AppProvider>
       {!hideNavbar && <Navbar />}
-      <AnimatePresence initial={false}>
+      <AnimatePresence initial={false} mode="wait">
         <motion.div
           key={pathname}
           initial={{ opacity: 0 }}
           animate={{ opacity: 1 }}
+          exit={{ opacity: 0 }}
           transition={{ duration: 0.15 }}
           className="flex-1"
         >