feat: schema for visa tracking (additive)

Adds VisaStatus enum, VisaApplication model 1:1 with AttendingMember
(cascade-delete), and Program.visaStatusVisibleToMembers Boolean
toggle. The model intentionally stores process metadata only — status,
optional nationality, key dates, free-text notes. Sensitive documents
(passport scans, invitation letters, decision papers) continue to flow
over email and are never persisted in the platform.

Migration is purely additive: CREATE TYPE / CREATE TABLE / ADD COLUMN /
ADD FK. No DROP / ALTER on existing data.

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

prisma/schema.prisma

@@ -487,7 +487,8 @@ model Program {
   settingsJson Json?         @db.JsonB
 
   // Grand-finale logistics
-  defaultAttendeeCap Int @default(3) // Max team members allowed at the grand finale per finalist team
+  defaultAttendeeCap         Int     @default(3) // Max team members allowed at the grand finale per finalist team
+  visaStatusVisibleToMembers Boolean @default(true) // Whether team members see their own visa status on the applicant dashboard
 
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
@@ -2726,9 +2727,10 @@ model AttendingMember {
   createdAt      DateTime @default(now())
   updatedAt      DateTime @updatedAt
 
-  confirmation FinalistConfirmation @relation(fields: [confirmationId], references: [id], onDelete: Cascade)
-  user         User                 @relation(fields: [userId], references: [id], onDelete: Cascade)
-  flightDetail FlightDetail?
+  confirmation    FinalistConfirmation @relation(fields: [confirmationId], references: [id], onDelete: Cascade)
+  user            User                 @relation(fields: [userId], references: [id], onDelete: Cascade)
+  flightDetail    FlightDetail?
+  visaApplication VisaApplication?
 
   @@unique([confirmationId, userId])
   @@index([userId])
@@ -2774,3 +2776,36 @@ model FlightDetail {
 
   @@index([status])
 }
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Grand-finale visa tracking (PR 4)
+// Process metadata only — no document storage. Passport scans / invitation
+// letters / decision documents are exchanged over email; this model just
+// records what stage the application is at, key dates, and free-text notes.
+// ─────────────────────────────────────────────────────────────────────────────
+
+enum VisaStatus {
+  NOT_NEEDED
+  REQUESTED
+  INVITATION_SENT
+  APPOINTMENT_BOOKED
+  GRANTED
+  DENIED
+}
+
+model VisaApplication {
+  id                String     @id @default(cuid())
+  attendingMemberId String     @unique // 1:1
+  status            VisaStatus @default(REQUESTED)
+  nationality       String? // self-declared, optional
+  invitationSentAt  DateTime?
+  appointmentAt     DateTime?
+  decisionAt        DateTime? // GRANTED or DENIED date
+  notes             String?    @db.Text
+  createdAt         DateTime   @default(now())
+  updatedAt         DateTime   @updatedAt
+
+  attendingMember AttendingMember @relation(fields: [attendingMemberId], references: [id], onDelete: Cascade)
+
+  @@index([status])
+}