Address remaining PR comments

src/app/components/VoiceRoomItem.svelte

@@ -7,6 +7,7 @@
   import {isMobileViewport} from "@lib/html"
   import ProfileCircle from "@app/components/ProfileCircle.svelte"
   import RoomName from "@app/components/RoomName.svelte"
+  import {errorMessage} from "@lib/util"
   import {pushToast} from "@app/util/toast"
   import {
     deriveVoiceParticipants,
@@ -46,10 +47,7 @@
     try {
       await joinVoiceRoom(url, h, joinAbortController.signal)
     } catch (e) {
-      if (e instanceof Error && e.message === "Join cancelled") return
-      if (e instanceof DOMException && e.name === "AbortError") return
-      const message = e instanceof Error ? e.message : String(e)
-      pushToast({theme: "error", message: `Failed to join voice room: ${message}`})
+      pushToast({theme: "error", message: `Failed to join voice room: ${errorMessage(e)}`})
     } finally {
       isJoining = false
       joinAbortController = undefined