ask_operator: ttl_seconds auto-cancel + remaining-time chip

manager can pass ttl_seconds to ask_operator. on submit, host
stores deadline_at = now + ttl in operator_questions (new column,
migrated via existing pragma_table_info pattern), spawns a tokio
task that sleeps until the deadline then resolves the question with
answer '[expired]' and fires the same OperatorAnswered helper event.
already-resolved races no-op silently.

dashboard renders a '⏳ MM:SS' chip on the question row when
deadline_at is set. format collapses seconds → s, < 1h → m s, ≥ 1h
→ h m. heartbeat refresh (5s) keeps the chip current; the operator
sees it tick down.

manager prompt + mcp tool description updated. journald viewer per
container queued in todo (separate task).

hive-c0re/assets/app.js

@@ -237,14 +237,23 @@
     const ul = el('ul', { class: 'questions' });
     for (const q of s.questions) {
       const li = el('li', { class: 'question' });
-      li.append(
-        el('div', { class: 'q-head' },
-          el('span', { class: 'msg-ts' }, fmt(q.asked_at)), ' ',
-          el('span', { class: 'msg-from' }, q.asker), ' ',
-          el('span', { class: 'msg-sep' }, 'asks:'),
-        ),
-        el('div', { class: 'q-body' }, q.question),
+      const head = el('div', { class: 'q-head' },
+        el('span', { class: 'msg-ts' }, fmt(q.asked_at)), ' ',
+        el('span', { class: 'msg-from' }, q.asker), ' ',
+        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));
+      }
+      li.append(head, el('div', { class: 'q-body' }, q.question));
       const f = el('form', {
         method: 'POST', action: '/answer-question/' + q.id,
         class: 'qform', 'data-async': '',

hive-c0re/assets/dashboard.css

@@ -296,6 +296,12 @@ summary:hover { color: var(--purple); }
 }
 .questions li.question:last-child { border-bottom: 0; }
 .questions .q-head { font-size: 0.9em; }
+.questions .q-ttl {
+  color: var(--amber);
+  margin-left: 0.4em;
+  font-size: 0.95em;
+  letter-spacing: 0.05em;
+}
 .questions .q-body {
   color: var(--fg);
   margin: 0.3em 0;