feat: add migration to make user tenantId nullable for platform-level superadmin

packages/db/prisma/migrations/20260415000000_make_user_tenantid_nullable/migration.sql

@@ -0,0 +1,12 @@
+-- AlterColumn: make tenantId nullable for platform-level users (superadmin)
+ALTER TABLE "users" ALTER COLUMN "tenantId" DROP NOT NULL;
+
+-- Drop existing FK and recreate with ON DELETE SET NULL
+ALTER TABLE "users" DROP CONSTRAINT "users_tenantId_fkey";
+ALTER TABLE "users" ADD CONSTRAINT "users_tenantId_fkey"
+  FOREIGN KEY ("tenantId") REFERENCES "tenants"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+
+-- Recreate unique index to allow multiple NULL tenantId values
+DROP INDEX IF EXISTS "users_tenantId_email_key";
+CREATE UNIQUE INDEX "users_tenantId_email_key" ON "users"("tenantId", "email") WHERE "tenantId" IS NOT NULL;
+CREATE UNIQUE INDEX "users_email_key" ON "users"("email") WHERE "tenantId" IS NULL;

packages/db/prisma/seed.ts

@@ -102,7 +102,7 @@ async function main() {
 
   // ─── Super Admin (platform-level, no tenant) ───────────
   const superAdmin = await prisma.user.create({
-    data: { tenantId: tenant.id, email: 'superadmin@fiberops.dev', password: await hashPassword('admin123!'), firstName: 'Super', lastName: 'Admin' },
+    data: { tenantId: null, email: 'superadmin@fiberops.dev', password: await hashPassword('admin123!'), firstName: 'Super', lastName: 'Admin' },
   });
   await prisma.userRole.create({ data: { userId: superAdmin.id, role: 'super_admin' } });
   console.log(`Super Admin: superadmin@fiberops.dev (super_admin)`);