feat: edit-attendees dialog + roster card on applicant dashboard

Adds applicant.getMyFinalistConfirmation query (returns roster + cutoff
metadata for the team's confirmation, or null). New AttendingMembersCard
shows the confirmed attendee list and surfaces an Edit dialog to the
team lead — disabled past the editable cutoff. Card auto-hides until the
confirmation reaches CONFIRMED status.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/(applicant)/applicant/page.tsx

@@ -18,6 +18,7 @@ import { Textarea } from '@/components/ui/textarea'
 import { CompetitionTimelineSidebar } from '@/components/applicant/competition-timeline'
 import { MentoringRequestCard } from '@/components/applicant/mentoring-request-card'
 import { MentorConversationCard } from '@/components/applicant/mentor-conversation-card'
+import { AttendingMembersCard } from '@/components/applicant/attending-members-card'
 import { AnimatedCard } from '@/components/shared/animated-container'
 import { ProjectLogoUpload } from '@/components/shared/project-logo-upload'
 import { Progress } from '@/components/ui/progress'
@@ -402,6 +403,9 @@ export default function ApplicantDashboardPage() {
             </AnimatedCard>
           ))}
 
+          {/* Grand finale attendee roster (auto-hides until confirmation status is CONFIRMED) */}
+          <AttendingMembersCard />
+
           {/* Conversation with assigned mentor (auto-hides when no mentor assigned) */}
           <MentorConversationCard projectId={project.id} />