fix: keep tape date visible and finish dual-review shell polish

Give the overview date its own class so mobile cannot hide it, keep mentor
subtitles fully readable, and align sentiment table header tokens.

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

app/frontend/shared/shell.css

@@ -3428,6 +3428,12 @@ body.sidebar-collapsed .status-bar {
   background: var(--hover);
 }
 
+.tape-detail-date,
+.overview-strip[data-overview-expanded="true"] .tape-detail-date {
+  display: flex;
+  flex-direction: column;
+}
+
 .tape-detail-item span {
   color: var(--text-3);
   font-size: var(--fs-aux);
@@ -3613,6 +3619,12 @@ body.sidebar-collapsed .status-bar {
     top: calc(var(--mobile-header-height) + 1px);
     grid-template-columns: repeat(2, minmax(0, 1fr));
   }
+
+  .tape-detail-date,
+  .overview-strip[data-overview-expanded="true"] .tape-detail-date {
+    display: flex;
+    flex-direction: column;
+  }
 }
 
 @media (max-width: 767px) {