dashboard: tick question TTL chip every second

The `⏳ MM:SS` chip on an asked-with-timeout question was rendered
once and then frozen — the operator saw stale info (e.g. 48s
sitting unchanged for the whole TTL window) (issue #335).

Stamp the deadline onto the chip as `data-deadline` and run a
single page-wide setInterval that refreshes every `.q-ttl[data-
deadline]`'s textContent each second. No re-render of the
questions section; no new state on the client. No-op when no
chips are on screen.

Also pulls the bucketed seconds-to-string logic into a
`formatTtl` helper so the renderer and the ticker share one
source of truth.

Closes #335.

hive-c0re/assets/app.js

@@ -1028,15 +1028,17 @@
         el('span', { class: 'msg-sep' }, 'asks:'),
       );
       if (q.deadline_at) {
-        const remaining = q.deadline_at - Math.floor(Date.now() / 1000);
-        let txt;
-        if (remaining <= 0) txt = 'expiring…';
-        else if (remaining < 60) txt = '⏳ ' + remaining + 's';
-        else if (remaining < 3600) txt = '⏳ ' + Math.floor(remaining / 60) + 'm '
-          + (remaining % 60) + 's';
-        else txt = '⏳ ' + Math.floor(remaining / 3600) + 'h '
-          + Math.floor((remaining % 3600) / 60) + 'm';
-        head.append(' ', el('span', { class: 'q-ttl' }, txt));
+        // Tag the chip with its deadline so the global 1s ticker
+        // (set up just below this function) can refresh the text
+        // without re-rendering the whole questions section
+        // (issue #335).
+        const ttlEl = el('span', {
+          class: 'q-ttl', 'data-deadline': String(q.deadline_at),
+        });
+        ttlEl.textContent = formatTtl(
+          q.deadline_at - Math.floor(Date.now() / 1000),
+        );
+        head.append(' ', ttlEl);
       }
       const qBody = el('div', { class: 'q-body' });
       appendLinkified(qBody, q.question, q.question_refs);
@@ -1156,6 +1158,35 @@
     }
   }
 
+  // Format a remaining-seconds count as the `⏳ …` TTL chip text on a
+  // question card. Bucketed at minutes / hours so a long deadline stays
+  // readable; "expiring…" once the deadline has passed (the host-side
+  // ttl-watchdog will fire shortly).
+  function formatTtl(remaining) {
+    if (remaining <= 0) return 'expiring…';
+    if (remaining < 60) return '⏳ ' + remaining + 's';
+    if (remaining < 3600) {
+      return '⏳ ' + Math.floor(remaining / 60) + 'm '
+        + (remaining % 60) + 's';
+    }
+    return '⏳ ' + Math.floor(remaining / 3600) + 'h '
+      + Math.floor((remaining % 3600) / 60) + 'm';
+  }
+
+  // Single page-wide ticker that refreshes every TTL chip in place
+  // each second (issue #335). Renderers stamp `data-deadline` on the
+  // chip; this just updates `textContent`, no re-render of the
+  // questions section. No-op when no chips are on screen, so the
+  // cost is negligible.
+  setInterval(() => {
+    const now = Math.floor(Date.now() / 1000);
+    document.querySelectorAll('.q-ttl[data-deadline]').forEach((node) => {
+      const deadline = Number(node.getAttribute('data-deadline'));
+      if (!Number.isFinite(deadline)) return;
+      node.textContent = formatTtl(deadline - now);
+    });
+  }, 1000);
+
   // ─── operator inbox (derived from the broker message stream) ───────────
   // No longer shipped on `/api/state.operator_inbox`. The dashboard
   // terminal's HiveTerminal feeds this via `onAnyEvent` — backfill from