Add mass selection in history: select-all, shift-click range, count badge

Select All checkbox in header row:
- Toggles all visible checkboxes at once
- Shows indeterminate state when partially selected
- Syncs with individual checkbox changes

Shift-click range selection:
- Hold Shift + click to select/deselect a range of rows
- Tracks last clicked index for range calculation

Selection count badge:
- Shows "N selected / M runs" in the run count badge when items selected
- Updates on every checkbox change

Header updated to include Score column matching the data grid.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

llm_team_ui.py

@@ -6834,7 +6834,7 @@ h1 span{color:var(--accent)}
 <!-- Run table -->
 <div class="run-table" id="run-table">
   <div class="run-row run-hdr">
-    <span></span><span>ID</span><span>Mode</span><span>Prompt</span><span>Models</span><span>Tags</span><span>Date</span>
+    <span><input type="checkbox" id="select-all-cb" onclick="toggleSelectAll(this)" style="width:14px;height:14px;accent-color:#e2b55a;cursor:pointer" title="Select all"></span><span>ID</span><span>Mode</span><span>Prompt</span><span>Models</span><span>Score</span><span>Tags</span><span>Date</span>
   </div>
   <div id="run-list"><div class="empty">Loading...</div></div>
 </div>
@@ -7030,13 +7030,13 @@ function renderTable(runs) {
   var el = document.getElementById('run-list');
   if (!runs.length) { el.textContent = ''; var e = document.createElement('div'); e.className = 'empty'; e.textContent = 'No runs found'; el.appendChild(e); return; }
   el.textContent = '';
-  runs.forEach(function(r) {
+  runs.forEach(function(r, idx) {
     var row = document.createElement('div');
     row.className = 'run-row' + (r.archived ? ' archived' : '');
     // Checkbox
     var cb = document.createElement('input'); cb.type = 'checkbox'; cb.dataset.id = r.id;
     cb.style.cssText = 'width:14px;height:14px;accent-color:#e2b55a;cursor:pointer';
-    cb.onclick = function(e){e.stopPropagation()};
+    cb.onclick = function(e){e.stopPropagation(); handleRowCheck(this, idx);};
     row.appendChild(cb);
     // ID
     var idEl = document.createElement('span'); idEl.className = 'run-id'; idEl.textContent = '#'+r.id; row.appendChild(idEl);
@@ -7290,6 +7290,34 @@ async function saveTags(id, tags, notes) {
   if (tags !== null) loadRuns();
 }
 
+function toggleSelectAll(masterCb) {
+  var checked = masterCb.checked;
+  document.querySelectorAll('#run-list input[type=checkbox]').forEach(function(cb) { cb.checked = checked; });
+  updateSelCount();
+}
+
+var _lastCheckedIdx = null;
+function handleRowCheck(cb, idx) {
+  // Shift-click range selection
+  if (window.event && window.event.shiftKey && _lastCheckedIdx !== null) {
+    var cbs = Array.from(document.querySelectorAll('#run-list input[type=checkbox]'));
+    var start = Math.min(_lastCheckedIdx, idx);
+    var end = Math.max(_lastCheckedIdx, idx);
+    for (var i = start; i <= end; i++) { cbs[i].checked = cb.checked; }
+  }
+  _lastCheckedIdx = idx;
+  updateSelCount();
+}
+
+function updateSelCount() {
+  var count = document.querySelectorAll('#run-list input[type=checkbox]:checked').length;
+  var total = document.querySelectorAll('#run-list input[type=checkbox]').length;
+  var masterCb = document.getElementById('select-all-cb');
+  if (masterCb) { masterCb.checked = count > 0 && count === total; masterCb.indeterminate = count > 0 && count < total; }
+  var badge = document.getElementById('run-count');
+  if (badge && count > 0) badge.textContent = count + ' selected / ' + total + ' runs';
+}
+
 function getSelectedIds() {
   var ids = [];
   document.querySelectorAll('#run-list input[type=checkbox]:checked').forEach(function(cb){ids.push(parseInt(cb.dataset.id))});