feat(frontend): Kalender-Modal – Teilnehmer-Chips + Auto-Vorauswahl

- Suche startet mit Organisator-Name vorbelegt → CRM zeigt sofort
  passende Kontakte
- Klickbare Teilnehmer-Chips ermöglichen schnellen Wechsel zwischen
  den Event-Attendees als Suchbegriff
- Aktiver Chip wird farblich hervorgehoben

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

packages/frontend/src/shell/DashboardCalendarTab.module.css

@@ -778,6 +778,40 @@
   margin-bottom: 0.5rem;
 }
 
+.attendeeSuggestions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.375rem;
+  margin-bottom: 0.625rem;
+}
+
+.attendeeChip {
+  padding: 0.2rem 0.625rem;
+  background: var(--color-bg);
+  border: 1px solid var(--color-border);
+  border-radius: 999px;
+  font-size: 0.75rem;
+  color: var(--color-text-secondary);
+  cursor: pointer;
+  transition: all 0.15s;
+  white-space: nowrap;
+  max-width: 180px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.attendeeChip:hover {
+  border-color: var(--color-primary);
+  color: var(--color-primary);
+}
+
+.attendeeChipActive {
+  background: rgba(59, 130, 246, 0.1);
+  border-color: var(--color-primary);
+  color: var(--color-primary);
+  font-weight: 500;
+}
+
 .contactSearchWrap {
   margin-bottom: 0.375rem;
 }

packages/frontend/src/shell/DashboardCalendarTab.tsx

@@ -92,7 +92,13 @@ function CalendarEventModal({
   onClose: () => void;
 }) {
   const createActivity = useCreateActivity();
-  const [contactSearch, setContactSearch] = useState('');
+
+  // Organisator oder erster Teilnehmer als Startsuchbegriff
+  const initialSearch =
+    event.organizer?.emailAddress.name ||
+    event.attendees?.[0]?.emailAddress.name ||
+    '';
+  const [contactSearch, setContactSearch] = useState(initialSearch);
   const [selectedContact, setSelectedContact] = useState<Contact | null>(null);
   const [actStatus, setActStatus] = useState<'idle' | 'loading' | 'success' | 'error'>('idle');
 
@@ -214,6 +220,31 @@ function CalendarEventModal({
         {actStatus !== 'success' ? (
           <div className={styles.contactSection}>
             <div className={styles.contactSectionTitle}>Als Aktivität bei Kontakt speichern</div>
+
+            {/* Teilnehmer-Chips für schnelle Auswahl */}
+            {event.attendees && event.attendees.length > 0 && (
+              <div className={styles.attendeeSuggestions}>
+                {event.attendees.slice(0, 7).map((a, i) => {
+                  const label = a.emailAddress.name || a.emailAddress.address;
+                  const isActive = contactSearch === label;
+                  return (
+                    <button
+                      key={i}
+                      type="button"
+                      className={`${styles.attendeeChip} ${isActive ? styles.attendeeChipActive : ''}`}
+                      onClick={() => {
+                        setContactSearch(label);
+                        setSelectedContact(null);
+                        setActStatus('idle');
+                      }}
+                    >
+                      {label}
+                    </button>
+                  );
+                })}
+              </div>
+            )}
+
             <div className={styles.contactSearchWrap}>
               <input
                 type="text"