Admin ring on comments/channel + pending-submissions dots on Admin tab & Submissions subtab

- adminBadge.js: add applyAdminRing(el, id) for surfaces that already place the
  star on a specific element and just need the ring.
- comments: ring + star on admin authors' avatars; round the comment avatar box
  so the ring reads as a circle.
- channel page: ring the inner rounded avatar box (star already on the wrap).
- Notification dots: red dot on the profile modal's Admin nav tab and on the
  Submissions subtab button when there are pending submissions, so admins know
  where to look. profileModalController.setSubmissionsUnreadIndicator toggles
  both (Admin nav dot gated on the tab being visible); driven from
  applyProfileNotificationDot off app._submissionsPending.

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

css/tailwind.source.css

@@ -2764,6 +2764,8 @@
     position: relative;
     inline-size: var(--comment-avatar-size);
     block-size: var(--comment-avatar-size);
+    /* rounded so the admin ring (box-shadow) reads as a circle */
+    border-radius: var(--radius-full);
   }
 
   .comment-thread__avatar img {
@@ -3561,6 +3563,30 @@
     display: block;
   }
 
+  /* Pending-submissions dot on the Admin pane's "Submissions" subtab. The
+     subtabs sit in a horizontal row, so this dot rides the top-right corner
+     (not the left edge like the vertical nav dots). */
+  .admin-subtab-has-dot {
+    position: relative;
+  }
+
+  .admin-subtab-dot {
+    position: absolute;
+    top: calc(-1 * var(--space-3xs));
+    right: calc(-1 * var(--space-3xs));
+    width: var(--space-sm);
+    height: var(--space-sm);
+    border-radius: var(--radius-full);
+    border: var(--border-width-hairline) solid var(--surface-panel);
+    background-color: var(--status-danger);
+    display: none;
+    pointer-events: none;
+  }
+
+  .admin-subtab-dot.is-visible {
+    display: block;
+  }
+
   .profile-modal__panes {
     display: flex;
     flex: 1 1 auto;