Disable rooms on mobile temporarily

src/app/components/VoiceRoomItem.svelte

@@ -5,6 +5,7 @@
   import SecondaryNavItem from "@lib/components/SecondaryNavItem.svelte"
   import ProfileCircle from "@app/components/ProfileCircle.svelte"
   import RoomName from "@app/components/RoomName.svelte"
+  import {isMobileViewport} from "@lib/html"
   import {pushToast} from "@app/util/toast"
   import {
     deriveVoiceParticipants,
@@ -26,6 +27,10 @@
   let joinAbortController: AbortController | undefined
 
   const handleClick = async () => {
+    if (isMobileViewport()) {
+      pushToast({theme: "error", message: "Voice rooms are not yet supported on mobile."})
+      return
+    }
     if (isActive) {
       await leaveVoiceRoom()
       return