Implement tenant import and RP auto login policies

backend/internal/bootstrap/bootstrap.go

@@ -29,6 +29,10 @@ func Run(db *gorm.DB) error {
 
 func migrateSchemas(db *gorm.DB) error {
 	slog.Info("[Bootstrap] Migrating database schemas...")
+	if err := dropLegacyTenantDomainUniqueIndex(db); err != nil {
+		return err
+	}
+
 	// Add all domain models here
 	return db.AutoMigrate(
 		&domain.Tenant{},
@@ -43,6 +47,20 @@ func migrateSchemas(db *gorm.DB) error {
 		&domain.KetoOutbox{},
 		&domain.SharedLink{},
 		&domain.DeveloperRequest{},
+		&domain.RPUserMetadata{},
 	// &domain.RelyingParty{}, // Removed: SSOT is Hydra + Keto
 	)
 }
+
+func dropLegacyTenantDomainUniqueIndex(db *gorm.DB) error {
+	if !db.Migrator().HasTable(&domain.TenantDomain{}) {
+		return nil
+	}
+	if !db.Migrator().HasIndex(&domain.TenantDomain{}, "idx_tenant_domains_domain") {
+		return nil
+	}
+	if err := db.Migrator().DropIndex(&domain.TenantDomain{}, "idx_tenant_domains_domain"); err != nil {
+		return fmt.Errorf("failed to drop legacy tenant domain unique index: %w", err)
+	}
+	return nil
+}