fix(frontend): paint video poster frames, clip round videos to circle

frontend/src/lib/components/profile/SharedMedia.svelte

@@ -9,6 +9,7 @@
   import Spinner from "$lib/components/ui/Spinner.svelte";
   import { formatListDate } from "$lib/format/datetime";
   import { formatBytes, mediaKindLabel } from "$lib/format/media";
+  import { poster } from "$lib/media/poster";
   import { accounts } from "$lib/stores/accounts.svelte";
   import { ui } from "$lib/stores/ui.svelte";
 
@@ -132,7 +133,13 @@
         {#if preview(item)?.state === "ready"}
           {@const ready = preview(item) as Extract<InlineMedia, { state: "ready" }>}
           {#if visualKind(item.kind) === "video"}
-            <video src={ready.url} muted preload="metadata"></video>
+            <video
+              src={ready.url}
+              muted
+              playsinline
+              preload="metadata"
+              use:poster
+            ></video>
             <span class="play"><Icon name="play" size="1.5rem" /></span>
           {:else}
             <img src={ready.url} alt="">