Simplify notification badges, improve performance (#57)

Co-authored-by: Jon Staab <shtaab@gmail.com>

src/app/components/SpaceMenuRoomItem.svelte

@@ -5,17 +5,15 @@
   import SecondaryNavItem from "@lib/components/SecondaryNavItem.svelte"
   import RoomNameWithImage from "@app/components/RoomNameWithImage.svelte"
   import {makeRoomPath} from "@app/util/routes"
-  import {notifications} from "@app/util/notifications"
   import {deriveShouldNotify} from "@app/core/state"
 
   interface Props {
     url: any
     h: any
-    notify?: boolean
     replaceState?: boolean
   }
 
-  const {url, h, notify = false, replaceState = false}: Props = $props()
+  const {url, h, replaceState = false}: Props = $props()
 
   const path = makeRoomPath(url, h)
   const shouldNotifyForSpace = deriveShouldNotify(url)
@@ -23,10 +21,7 @@
   const showDifferenceIcon = $derived($shouldNotifyForRoom !== $shouldNotifyForSpace)
 </script>
 
-<SecondaryNavItem
-  href={path}
-  {replaceState}
-  notification={notify ? $notifications.has(path) : false}>
+<SecondaryNavItem href={path} {replaceState}>
   <RoomNameWithImage {url} {h} />
   {#if showDifferenceIcon}
     <Icon icon={$shouldNotifyForRoom ? VolumeLoud : VolumeCross} size={4} class="opacity-50" />