feat: mobile UX, admin polish, rate limiting, and media assets

- Mobile responsiveness improvements across admin and public sections
- Admin: bookings modal, open-day page, team page, layout polish
- Added rate limiting, CSRF hardening, auth-edge improvements
- Scroll reveal, floating contact, back-to-top, Yandex map fixes
- Schedule filters refactor, team profile/info component updates
- New useTrainerPhotos hook
- Added class, team, master-class, and news images

src/components/sections/OpenDay.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useMemo } from "react";
+import { useTrainerPhotos } from "@/hooks/useTrainerPhotos";
 import Image from "next/image";
 import { Calendar, Sparkles, User, MapPin } from "lucide-react";
 import { SectionHeading } from "@/components/ui/SectionHeading";
@@ -33,15 +34,7 @@ export function OpenDay({ data, popups, teamMembers, locations }: OpenDayProps)
   const { event, classes } = data;
   const [signup, setSignup] = useState<{ classId: number; label: string } | null>(null);
 
-  const trainerPhotos = useMemo(() => {
-    const map: Record<string, string> = {};
-    if (teamMembers) {
-      for (const m of teamMembers) {
-        if (m.image) map[m.name] = m.image;
-      }
-    }
-    return map;
-  }, [teamMembers]);
+  const trainerPhotos = useTrainerPhotos(teamMembers);
 
   // Group classes by hall
   const hallGroups = useMemo(() => {