refactor(auth): modularize auth plugin with physical subpackages and decoupled services

backend/plugins/domain/auth/dao/external_account.go

@@ -0,0 +1,38 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package dao provides data access objects and caching for the auth domain plugin.
+package dao
+
+import (
+	"Wavelet/plugins/domain/auth/model/entity"
+	"context"
+)
+
+// FindExternalAccount 查询指定认证源的外部账号绑定
+func (d *DAO) FindExternalAccount(ctx context.Context, authSourceID uint64, externalID string) (*entity.ExternalAccount, error) {
+	var account entity.ExternalAccount
+	if err := d.DB(ctx).Where("auth_source_id = ? AND external_id = ?", authSourceID, externalID).First(&account).Error; err != nil {
+		return nil, err
+	}
+	return &account, nil
+}
+
+// BindExternalAccount 绑定外部账号
+func (d *DAO) BindExternalAccount(ctx context.Context, account *entity.ExternalAccount) error {
+	return d.DB(ctx).Create(account).Error
+}
+
+// ListExternalAccountsByUserID 获取用户绑定的所有外部账号
+func (d *DAO) ListExternalAccountsByUserID(ctx context.Context, userID uint64) ([]entity.ExternalAccount, error) {
+	var accounts []entity.ExternalAccount
+	if err := d.DB(ctx).Where("user_id = ?", userID).Find(&accounts).Error; err != nil {
+		return nil, err
+	}
+	return accounts, nil
+}
+
+// UnbindExternalAccount 解绑外部账号
+func (d *DAO) UnbindExternalAccount(ctx context.Context, id, userID uint64) error {
+	return d.DB(ctx).Where("id = ? AND user_id = ?", id, userID).Delete(&entity.ExternalAccount{}).Error
+}