Calendar + date cards: render webhook HTML (sanitize, links open in new tab)

css/styles.css

@@ -1497,6 +1497,8 @@ TELEGRAM BANNER
   white-space: nowrap;
 }
 .calendar-event-headline { flex: 1; color: #1c1e21; }
+.calendar-event-headline a { color: #1877f2; text-decoration: none; font-weight: 600; }
+.calendar-event-headline a:hover { text-decoration: underline; }
 .calendar-event-time { color: #65676b; white-space: nowrap; }
 
 /* ========================================

js/main.js

@@ -981,7 +981,7 @@ function renderDates(events) {
     
     card.innerHTML = '<div class="date-header">' +
       '<div class="date-icon">📅</div>' +
-      '<h3 class="date-headline">' + escapeHtml(event.headline || 'Event') + '</h3>' +
+      '<h3 class="date-headline">' + sanitizeHtml(event.headline || 'Event') + '</h3>' +
       '</div><div class="date-info">' +
       '<div class="date-row">' +
       '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="3" y="4" width="18" height="18" rx="2" ry="2"/><line x1="16" y1="2" x2="16" y2="6"/><line x1="8" y1="2" x2="8" y2="6"/><line x1="3" y1="10" x2="21" y2="10"/></svg>' +
@@ -1004,6 +1004,34 @@ function renderDates(events) {
 // ========================================
 function pad2(n) { return String(n).padStart(2, '0'); }
 
+// Webhook text may contain simple HTML (e.g. links). Sanitize before injecting:
+// strip script/iframe/... tags, on* handlers and javascript: URLs; force
+// links to open in a new tab.
+function sanitizeHtml(html) {
+  const div = document.createElement('div');
+  div.innerHTML = String(html || '');
+  div.querySelectorAll('script, style, iframe, object, embed, link, meta').forEach(n => n.remove());
+  const walk = (node) => {
+    Array.from(node.childNodes || []).forEach(child => {
+      if (child.nodeType !== 1) return;
+      Array.from(child.attributes || []).forEach(attr => {
+        const name = attr.name.toLowerCase();
+        const val = (attr.value || '').replace(/\s+/g, '').toLowerCase();
+        if (name.startsWith('on') || ((name === 'href' || name === 'src') && val.startsWith('javascript:'))) {
+          child.removeAttribute(attr.name);
+        }
+      });
+      if (child.tagName === 'A') {
+        child.setAttribute('target', '_blank');
+        child.setAttribute('rel', 'noopener');
+      }
+      walk(child);
+    });
+  };
+  walk(div);
+  return div.innerHTML;
+}
+
 function initCalendar() {
   renderCalendar();
 }
@@ -1028,7 +1056,7 @@ function renderCalendar() {
     const timeStr = pad2(sd.getHours()) + ':' + pad2(sd.getMinutes()) +
       (ed ? '–' + pad2(ed.getHours()) + ':' + pad2(ed.getMinutes()) : '');
     list += '<li><span class="calendar-event-date">' + dateStr + '</span>' +
-      '<span class="calendar-event-headline">' + escapeHtml(ev.headline || 'Event') + '</span>' +
+      '<span class="calendar-event-headline">' + sanitizeHtml(ev.headline || 'Event') + '</span>' +
       '<span class="calendar-event-time">' + timeStr + '</span></li>';
   });
   list += '</ul>';