fix(agenda): habilita selectable/select para abrir modal de novo agendamento no slot

- selectable + selectMirror + select (clicar/arrastar intervalo livre abre o modal)
- complementa dateClick; útil com a agenda cheia de eventos do Google

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/views/AgendaView.tsx

@@ -438,6 +438,8 @@ export const AgendaView: React.FC<{ onNavigate?: (view: string) => void }> = ({
     }, [agendamentos, dentists, googleEvents]);
 
     const handleDateClick = (arg: any) => { setReagendarPatient(null); setSelectedAppointment(null); setSelectedDateInfo(arg); setIsModalOpen(true); };
+    // Selecionar (clicar/arrastar) um intervalo livre também abre o modal de novo agendamento.
+    const handleDateSelect = (info: any) => { setReagendarPatient(null); setSelectedAppointment(null); setSelectedDateInfo({ dateStr: info.startStr }); setIsModalOpen(true); };
 
     const handleReagendarPendencia = (p: any) => {
         setShowPendencias(false);
@@ -612,6 +614,9 @@ export const AgendaView: React.FC<{ onNavigate?: (view: string) => void }> = ({
                     slotMaxTime="19:00:00"
                     allDaySlot={false}
                     events={events}
+                    selectable={true}
+                    selectMirror={true}
+                    select={handleDateSelect}
                     dateClick={handleDateClick}
                     eventClick={handleEventClick}
                     height="100%"