feat: add Записаться button to group cards with pre-filled Instagram DM

- BookingModal now accepts optional groupInfo for pre-filled message
- Trainer profile: each group card has Записаться button
- Schedule group view: each group card has Записаться button
- Message includes class type, trainer, days, and time

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

src/components/sections/Schedule.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useMemo, useCallback } from "react";
+import { BookingModal } from "@/components/ui/BookingModal";
 import { CalendarDays, Users, LayoutGrid } from "lucide-react";
 import { SectionHeading } from "@/components/ui/SectionHeading";
 import { Reveal } from "@/components/ui/Reveal";
@@ -28,6 +29,7 @@ export function Schedule({ data: schedule, classItems }: ScheduleProps) {
   const [filterStatus, setFilterStatus] = useState<StatusFilter>("all");
   const [filterTime, setFilterTime] = useState<TimeFilter>("all");
   const [filterDaySet, setFilterDaySet] = useState<Set<string>>(new Set());
+  const [bookingGroup, setBookingGroup] = useState<string | null>(null);
 
   const isAllMode = locationMode === "all";
 
@@ -329,9 +331,15 @@ export function Schedule({ data: schedule, classItems }: ScheduleProps) {
             filterTrainer={filterTrainer}
             setFilterTrainer={setFilterTrainerFromCard}
             showLocation={isAllMode}
+            onBook={setBookingGroup}
           />
         </Reveal>
       )}
+      <BookingModal
+        open={bookingGroup !== null}
+        onClose={() => setBookingGroup(null)}
+        groupInfo={bookingGroup ?? undefined}
+      />
     </section>
   );
 }