submissions(#23): admin "Submissions" sub-tab (approve/deny)

The headline: an admin surface to triage the structured submissions.
- profile-modal.html: "Submissions" sub-tab button + #adminSubmissionsSection
  (refresh + loading/empty + list), alongside Whitelist/Blacklist/Blocked
  videos/Moderators.
- ProfileAdminController: adds "submissions" to the sub-tab machinery (button +
  section maps, selectAdminSubtab dispatch, refreshAdminPaneState populate), gates
  the tab on FEATURE_SUBMISSIONS, and wires the list/refresh listeners.
- js/ui/profileModal/submissionsSection.js (extracted to keep the controller under
  the 1200-line cap, like blockedVideosSection.js): populate/render + approve/deny.
  Approve (applications only) → accessControl.addToWhitelist(actor, applicant) +
  markSubmissionResolved(approved) + refresh the whitelist; Deny/Dismiss →
  markSubmissionResolved(denied). Optimistic remove; re-sync on failure. Cards show
  the type badge + claimed applicant + body.
- tailwind.source.css: .submission-card* (token-only).

Gated by FEATURE_SUBMISSIONS (tab hidden when off). Lint + build clean;
profile-modal-controller tests 26/26.

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

css/tailwind.source.css

@@ -3168,6 +3168,60 @@
     flex-shrink: 0;
   }
 
+  /* #23: admin Submissions cards. */
+  .submission-card {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-2xs);
+    padding: var(--space-sm);
+    border: var(--border-width-hairline) solid var(--color-border-subtle);
+    border-radius: var(--radius-md);
+    background-color: var(--color-page-alt);
+  }
+
+  .submission-card + .submission-card {
+    margin-block-start: var(--space-2xs);
+  }
+
+  .submission-card__head {
+    display: flex;
+    align-items: center;
+    gap: var(--space-sm);
+    flex-wrap: wrap;
+  }
+
+  .submission-card__type {
+    padding-block: var(--space-3xs);
+    padding-inline: var(--space-2xs);
+    border-radius: var(--radius-full);
+    font-size: var(--font-size-2xs);
+    font-weight: 600;
+    color: var(--color-white);
+    background-color: var(--color-accent-strong);
+  }
+
+  .submission-card__applicant {
+    min-inline-size: 0;
+    font-size: var(--font-size-2xs);
+    color: var(--color-text-muted);
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+  }
+
+  .submission-card__body {
+    margin: 0;
+    font-size: var(--font-size-sm);
+    color: var(--color-text);
+    white-space: pre-wrap;
+    word-break: break-word;
+  }
+
+  .submission-card__actions {
+    display: flex;
+    gap: var(--space-2xs);
+  }
+
   /* #43: always-visible active-identity pill. Rendered after the header in
      flow and pulled up with a negative block-start margin so it sits half-on /
      half-off the header divider — every pane shows who you're acting as. */