feat(database): UserDeletionAuditLog + cascade FKs for admin user delete

internal-packages/database/prisma/migrations/20260428112409_admin_user_deletion/migration.sql

@@ -0,0 +1,35 @@
+-- DropForeignKey
+ALTER TABLE "public"."MfaBackupCode" DROP CONSTRAINT "MfaBackupCode_userId_fkey";
+
+-- DropForeignKey
+ALTER TABLE "public"."PersonalAccessToken" DROP CONSTRAINT "PersonalAccessToken_userId_fkey";
+
+-- CreateTable
+CREATE TABLE "public"."UserDeletionAuditLog" (
+    "id" TEXT NOT NULL,
+    "adminUserId" TEXT NOT NULL,
+    "adminEmail" TEXT NOT NULL,
+    "targetUserId" TEXT NOT NULL,
+    "targetEmail" TEXT NOT NULL,
+    "softDeletedOrgIds" TEXT[],
+    "reason" TEXT,
+    "ipAddress" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "UserDeletionAuditLog_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE INDEX "UserDeletionAuditLog_adminUserId_idx" ON "public"."UserDeletionAuditLog"("adminUserId");
+
+-- CreateIndex
+CREATE INDEX "UserDeletionAuditLog_targetUserId_idx" ON "public"."UserDeletionAuditLog"("targetUserId");
+
+-- CreateIndex
+CREATE INDEX "UserDeletionAuditLog_createdAt_idx" ON "public"."UserDeletionAuditLog"("createdAt");
+
+-- AddForeignKey
+ALTER TABLE "public"."MfaBackupCode" ADD CONSTRAINT "MfaBackupCode_userId_fkey" FOREIGN KEY ("userId") REFERENCES "public"."User"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "public"."PersonalAccessToken" ADD CONSTRAINT "PersonalAccessToken_userId_fkey" FOREIGN KEY ("userId") REFERENCES "public"."User"("id") ON DELETE CASCADE ON UPDATE CASCADE;

internal-packages/database/prisma/schema.prisma

@@ -74,7 +74,7 @@ model MfaBackupCode {
   /// Hash of the actual code
   code String
 
-  user   User   @relation(fields: [userId], references: [id])
+  user   User   @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)
   userId String
 
   usedAt DateTime?
@@ -131,7 +131,7 @@ model PersonalAccessToken {
   /// This is used to find the token in the database
   hashedToken String @unique
 
-  user   User   @relation(fields: [userId], references: [id])
+  user   User   @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)
   userId String
 
   revokedAt      DateTime?
@@ -2590,6 +2590,32 @@ model ImpersonationAuditLog {
   @@index([createdAt])
 }
 
+model UserDeletionAuditLog {
+  id String @id @default(cuid())
+
+  /// Denormalized — audit row must survive after the target user is deleted.
+  /// No FKs to User; store IDs and emails as plain text.
+  adminUserId  String
+  adminEmail   String
+  targetUserId String
+  targetEmail  String
+
+  /// Organization IDs that were soft-deleted as part of this user delete
+  /// (orgs where the deleted user was the sole member).
+  softDeletedOrgIds String[]
+
+  /// Optional: ticket link / GDPR request id / free-text SE note.
+  reason String?
+
+  ipAddress String?
+
+  createdAt DateTime @default(now())
+
+  @@index([adminUserId])
+  @@index([targetUserId])
+  @@index([createdAt])
+}
+
 enum CustomerQuerySource {
   DASHBOARD
   API