Reassert hidden display:none for panel-stats rows

The .panel-stats .stat rule sets display:flex and out-specifies the UA
[hidden] { display:none } stylesheet, so toggling .hidden on the
peer-count stat left the row visible with an empty value when
seen_by_others was null or zero. Mirror the same explicit override
already used for .mil-chip / .pop-peer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: MrSuttonmann

app/static/detail_panel.css

@@ -391,6 +391,10 @@
     display: flex; flex-direction: column; gap: 1px;
     font-variant-numeric: tabular-nums;
   }
+  /* Reassert the UA [hidden] rule — the .stat selector above sets
+     display: flex, which would otherwise win over the (lower-specificity)
+     attribute selector and leave hidden stats visible with empty values. */
+  .panel-stats .stat[hidden] { display: none; }
   .panel-stats .stat-label {
     font-size: 9px; color: var(--muted);
     text-transform: uppercase; letter-spacing: 0.6px;