Admin ring + star across avatars (identity, switcher, cards, player, DMs)

Add a reusable decorateAdminAvatar(avatarEl, id) that applies BOTH the gold
ring (box-shadow, not clipped by the avatar's overflow) and the corner star
(hung off a non-clipped .admin-avatar-wrap it ensures around the avatar).
Idempotent; works on attached or freshly-built detached avatars.

Wired onto:
- profile modal "Acting as" identity pill
- account-switcher saved-profile avatars
- video card creator avatars
- video player creator avatar
- DM conversation list + message bubbles (upgraded from star-only to ring+star)

adminBadge.js: split the star decision from its DOM (setAdminStar) so the
ring and star share one isAdminActor check; added ADMIN_RING_CLASS /
ADMIN_WRAP_CLASS. tests: decorateAdminAvatar (wrap/ring/star, idempotency,
non-admin, detached).

Co-Authored-By: Claude Opus 4.8 <[email protected]>

css/tailwind.source.css

@@ -280,6 +280,23 @@
     left: var(--space-2xs);
   }
 
+  /* Non-clipped relative shell that decorateAdminAvatar wraps around a circular
+     avatar so the corner star isn't clipped. Sizes to the avatar it holds. */
+  .admin-avatar-wrap {
+    position: relative;
+    display: inline-flex;
+    flex-shrink: 0;
+  }
+
+  /* Gold ring hugging an admin avatar. A thin page-colored gap makes it read as
+     a ring, not a border. box-shadow isn't clipped by the avatar's own
+     overflow, so it works on clipped circular avatars. */
+  .admin-ring {
+    box-shadow:
+      0 0 0 var(--border-width-hairline) var(--color-page),
+      0 0 0 calc(var(--border-width-hairline) * 3) var(--status-warning);
+  }
+
   /* Gold ring around the avatar when the logged-in user is an admin — the
      unmistakable "you're an admin" signal on your own profile button. A thin
      page-colored gap separates the avatar from the ring so it reads as a ring,