fix: child toggle always visible; showDetail fetches missing tickets; extraTickets cache

- Toggle now shows whenever a ticket has children (not gated on local filter visibility)
- showDetail() is async and fetches from API when ticket isn't in the local array,
  caching results in extraTickets so subsequent navigation and row rendering work
- Sidepane async child fetch stores results in extraTickets for the same reason

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

corvid/templates/tickets_base.html

@@ -527,6 +527,7 @@ let currentTicket = null;
 let expandedParents = new Set();
 let currentAttach = null;
 let tickets = [];
+let extraTickets = {};
 let attachments = [];
 let environments = [];
 let currentEnvironmentId = null;
@@ -699,17 +700,20 @@ async function loadTickets() {
   }
 }
 
+function getTicketById(id) {
+  return tickets.find(t => t.id === id) || extraTickets[id] || null;
+}
+
 function renderTicketRow(t) {
-  const visibleChildIds = (t.child_ids || []).filter(cid => tickets.some(c => c.id === cid));
   const totalChildCount = (t.child_ids || []).length;
-  const visibleCount = visibleChildIds.length;
+  const knownChildIds = (t.child_ids || []).filter(cid => getTicketById(cid));
   const expanded = expandedParents.has(t.id);
   return `
     <div class="ticket-row" onclick="showDetail(${t.id}); event.stopPropagation()">
       <div class="tr-top">
         <span class="tr-id">${t.human_id}</span>
         <span class="tr-title">${escHtml(t.title)}</span>
-        ${totalChildCount ? `${visibleCount ? `<button class="child-toggle" onclick="toggleChildren(${t.id}); event.stopPropagation()" title="${expanded ? 'Collapse' : 'Expand'} child tickets">${expanded ? '▾' : '▸'}</button>` : ''}<span class="child-count">${totalChildCount}</span>` : ''}
+        ${totalChildCount ? `<button class="child-toggle" onclick="toggleChildren(${t.id}); event.stopPropagation()" title="${expanded ? 'Collapse' : 'Expand'} child tickets">${expanded ? '▾' : '▸'}</button><span class="child-count">${totalChildCount}</span>` : ''}
       </div>
       <div class="tr-bottom">
         ${typeBadge(t.type)}
@@ -722,7 +726,7 @@ function renderTicketRow(t) {
         ${t.attachment_count ? `<span class="tr-sep">·</span><span class="att-chip">${t.attachment_count} file${t.attachment_count !== 1 ? 's' : ''}</span>` : ''}
       </div>
     </div>
-    ${visibleCount && expanded ? `<div class="child-rows">${visibleChildIds.map(cid => renderTicketRow(tickets.find(c => c.id === cid))).join('')}</div>` : ''}
+    ${knownChildIds.length && expanded ? `<div class="child-rows">${knownChildIds.map(cid => renderTicketRow(getTicketById(cid))).join('')}</div>` : ''}
   `;
 }
 
@@ -753,9 +757,14 @@ function renderList() {
   list.innerHTML = roots.map(renderTicketRow).join('');
 }
 
-function showDetail(id) {
+async function showDetail(id) {
-  currentTicket = tickets.find(t => t.id === id);
+  currentTicket = getTicketById(id);
-  if (!currentTicket) return;
+  if (!currentTicket) {
+    try {
+      currentTicket = await api(`/api/tickets/${id}`);
+      extraTickets[id] = currentTicket;
+    } catch(e) { return; }
+  }
   const t = currentTicket;
   document.getElementById('d-human-id').textContent = t.human_id;
   document.getElementById('d-title').textContent = t.title;
@@ -782,16 +791,17 @@ function showDetail(id) {
   if (t.child_ids && t.child_ids.length) {
     const childList = document.getElementById('d-children-list');
     childList.innerHTML = t.child_ids.map(cid => {
-      const child = tickets.find(c => c.id === cid);
+      const child = getTicketById(cid);
       const label = child ? `${child.human_id} ${escHtml(child.title)}` : `#${cid}`;
       return `<a class="child-link" id="child-ref-${cid}" onclick="showDetail(${cid}); event.stopPropagation()">${label}</a>`;
     }).join('');
     childWrap.style.display = '';
-    // Fetch any children that aren't in the current filtered ticket list
+    // Fetch any children not in the local ticket list and cache them
     t.child_ids.forEach(async cid => {
-      if (!tickets.find(c => c.id === cid)) {
+      if (!getTicketById(cid)) {
         try {
           const child = await api(`/api/tickets/${cid}`);
+          extraTickets[child.id] = child;
           const el = document.getElementById(`child-ref-${cid}`);
           if (el) el.textContent = `${child.human_id} ${child.title}`;
         } catch(e) { /* keep fallback label */ }