Add notification bell system and MOPC onboarding form

Notification System:
- Add InAppNotification and NotificationEmailSetting database models
- Create notification service with 60+ notification types for all user roles
- Add notification router with CRUD endpoints
- Build NotificationBell UI component with dropdown and unread count
- Integrate bell into admin, jury, mentor, and observer navs
- Add notification email settings admin UI in Settings > Notifications
- Add notification triggers to filtering router (complete/failed)
- Add sendNotificationEmail function to email library
- Add formatRelativeTime utility function

MOPC Onboarding Form:
- Create /apply landing page with auto-redirect for single form
- Create seed script for MOPC 2026 application form (6 steps)
- Create seed script for default notification email settings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/components/layouts/mentor-nav.tsx

@@ -18,6 +18,7 @@ import {
 } from '@/components/ui/dropdown-menu'
 import { BookOpen, Home, LogOut, Menu, Settings, User, Users, X } from 'lucide-react'
 import { Logo } from '@/components/shared/logo'
+import { NotificationBell } from '@/components/shared/notification-bell'
 
 interface MentorNavProps {
   user: {
@@ -84,6 +85,7 @@ export function MentorNav({ user }: MentorNavProps) {
 
             {/* User menu & mobile toggle */}
             <div className="flex items-center gap-2">
+              <NotificationBell />
               <DropdownMenu>
                 <DropdownMenuTrigger asChild>
                   <Button