Jury dashboard compact layout, assignment redesign, auth fixes

- Jury dashboard: collapse zero-assignment state into single welcome card
  with inline quick actions; merge completion bar into stats row; tighten spacing
- Manual assignment: replace tiny Dialog modal with inline collapsible section
  featuring searchable juror combobox and multi-select project list with bulk assign
- Fix applicant invite URL path (/auth/accept-invite -> /accept-invite)
- Add APPLICANT role redirect to /my-submission from root page
- Add Applicant label to accept-invite role display
- Fix a/an grammar in invitation emails and accept-invite page
- Set-password page: use MOPC logo instead of lock icon
- Notification bell: remove filter tabs, always show all notifications

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

src/app/(auth)/accept-invite/page.tsx

@@ -85,6 +85,7 @@ function AcceptInviteContent() {
       case 'PROGRAM_ADMIN': return 'Program Admin'
       case 'MENTOR': return 'Mentor'
       case 'OBSERVER': return 'Observer'
+      case 'APPLICANT': return 'Applicant'
       default: return role
     }
   }
@@ -182,7 +183,7 @@ function AcceptInviteContent() {
         </CardTitle>
         <CardDescription className="text-base">
           You&apos;ve been invited to join the Monaco Ocean Protection Challenge platform
-          {user?.role ? ` as a ${getRoleLabel(user.role)}.` : '.'}
+          {user?.role ? ` as ${/^[aeiou]/i.test(getRoleLabel(user.role)) ? 'an' : 'a'} ${getRoleLabel(user.role)}.` : '.'}
         </CardDescription>
       </CardHeader>
       <CardContent className="space-y-4">