feat(copilot): complete runtime provider configuration

backend/internal/repository/installation_config_repo.go

@@ -77,6 +77,26 @@ func (r *InstallationConfigRepo) UpsertByName(ctx context.Context, name, value s
 	return r.db.WithContext(ctx).Create(&model.InstallationConfig{Name: name, Value: value}).Error
 }
 
+// UpsertValues atomically updates a set of stable installation config keys.
+func (r *InstallationConfigRepo) UpsertValues(ctx context.Context, values map[string]string) error {
+	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		for name, value := range values {
+			result := tx.Model(&model.InstallationConfig{}).
+				Where("name = ?", name).
+				Update("value", value)
+			if result.Error != nil {
+				return result.Error
+			}
+			if result.RowsAffected == 0 {
+				if err := tx.Create(&model.InstallationConfig{Name: name, Value: value}).Error; err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+}
+
 // Delete removes an InstallationConfig record by primary key (soft-delete via Base.DeletedAt).
 func (r *InstallationConfigRepo) Delete(ctx context.Context, id uint) error {
 	return r.db.WithContext(ctx).Delete(&model.InstallationConfig{}, id).Error