Merge family absence flows while preserving security hardening

prisma/migrations/20261010000000_family_invitation_flows/migration.sql

@@ -0,0 +1,13 @@
+-- Family invitation delivery status; applied before the restricted runtime starts.
+ALTER TABLE "invitations"
+  ADD COLUMN "userId" TEXT,
+  ADD COLUMN "sentAt" TIMESTAMP(3),
+  ADD COLUMN "lastAttemptAt" TIMESTAMP(3),
+  ADD COLUMN "leaseUntil" TIMESTAMP(3),
+  ADD COLUMN "attempts" INTEGER NOT NULL DEFAULT 0,
+  ADD COLUMN "failed" BOOLEAN NOT NULL DEFAULT false;
+CREATE UNIQUE INDEX "invitations_userId_key" ON "invitations"("userId");
+ALTER TABLE "invitations" ADD CONSTRAINT "invitations_userId_fkey"
+  FOREIGN KEY ("userId") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "invitations" ADD CONSTRAINT "invitations_userId_tenant_fkey"
+  FOREIGN KEY ("userId", "kitaId") REFERENCES "users"("id", "kitaId") ON DELETE CASCADE ON UPDATE NO ACTION;

prisma/schema.prisma

@@ -268,6 +268,7 @@ model User {
 
   mitbringselItems   MitbringselItem[]
   invitationsCreated Invitation[]                 @relation("InvitationCreator")
+  familyInvitation   Invitation?                  @relation("InvitationRecipient")
   auditLogsAuthored  AuditLog[]                   @relation("AuditLogActor")
   staffProfile       StaffProfile?
   staffNotifications StaffNotification[]
@@ -749,10 +750,19 @@ model Invitation {
   email String
   role  UserRole @default(ELTERN)
 
+  // Nullable for older, unlinked invitations. Family invitations belong to a user.
+  userId String? @unique
+  user   User?   @relation("InvitationRecipient", fields: [userId], references: [id], onDelete: Cascade)
+
   token      String           @unique
   status     InvitationStatus @default(PENDING)
   expiresAt  DateTime
   acceptedAt DateTime?
+  sentAt        DateTime?
+  lastAttemptAt DateTime?
+  leaseUntil    DateTime?
+  attempts      Int       @default(0)
+  failed        Boolean   @default(false)
 
   invitedById String?
   invitedBy   User?   @relation("InvitationCreator", fields: [invitedById], references: [id], onDelete: SetNull)