add room mentions and clickable room/relay refs

src/app/editor/RoomSuggestion.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+  import {displayRelayUrl} from "@welshman/util"
+  import RoomNameWithImage from "@app/components/RoomNameWithImage.svelte"
+  import {splitRoomId} from "@app/core/state"
+
+  type Props = {
+    value: string
+  }
+
+  const {value}: Props = $props()
+  const [url = "", h = ""] = splitRoomId(value)
+</script>
+
+<div class="max-w-full overflow-hidden text-ellipsis flex flex-col">
+  <RoomNameWithImage {url} {h} />
+  <span class="text-primary text-sm">{displayRelayUrl(url)}<span> </span></span>
+</div>