feat: 实现 C 端完整认证系统（client-auth-system）

实现面向个人客户的 7 个认证接口（A1-A7），覆盖资产验证、
微信公众号/小程序登录、手机号绑定/换绑、退出登录完整流程。

主要变更：
- 新增 PersonalCustomerOpenID 模型，支持多 AppID 多 OpenID 管理
- 实现有状态 JWT（JWT + Redis 双重校验），支持服务端主动失效
- 扩展微信 SDK：小程序 Code2Session + 3 个 DB 动态工厂函数
- 实现 A1 资产验证 IP 限流（30/min）和 A4 三层验证码限流
- 新增 7 个错误码（1180-1186）和 6 个 Redis Key 函数
- 注册 /api/c/v1/auth/* 下 7 个端点并更新 OpenAPI 文档
- 数据库迁移 000083：新建 tb_personal_customer_openid 表

internal/model/dto/client_auth_dto.go

@@ -0,0 +1,103 @@
+package dto
+
+// ========================================
+// A1 资产验证
+// ========================================
+
+// VerifyAssetRequest A1 资产验证请求
+type VerifyAssetRequest struct {
+	Identifier string `json:"identifier" validate:"required,min=1,max=50" required:"true" minLength:"1" maxLength:"50" description:"资产标识符（SN/IMEI/虚拟号/ICCID/MSISDN）"`
+}
+
+// VerifyAssetResponse A1 资产验证响应
+type VerifyAssetResponse struct {
+	AssetToken string `json:"asset_token" description:"资产令牌（5分钟有效）"`
+	ExpiresIn  int    `json:"expires_in" description:"过期时间（秒）"`
+}
+
+// ========================================
+// A2 公众号登录
+// ========================================
+
+// WechatLoginRequest A2 公众号登录请求
+type WechatLoginRequest struct {
+	Code       string `json:"code" validate:"required" required:"true" description:"微信OAuth授权码"`
+	AssetToken string `json:"asset_token" validate:"required" required:"true" description:"A1返回的资产令牌"`
+}
+
+// WechatLoginResponse A2/A3 登录统一响应
+type WechatLoginResponse struct {
+	Token         string `json:"token" description:"登录JWT令牌"`
+	NeedBindPhone bool   `json:"need_bind_phone" description:"是否需要绑定手机号"`
+	IsNewUser     bool   `json:"is_new_user" description:"是否新创建用户"`
+}
+
+// ========================================
+// A3 小程序登录
+// ========================================
+
+// MiniappLoginRequest A3 小程序登录请求
+type MiniappLoginRequest struct {
+	Code       string `json:"code" validate:"required" required:"true" description:"小程序登录凭证"`
+	AssetToken string `json:"asset_token" validate:"required" required:"true" description:"A1返回的资产令牌"`
+	Nickname   string `json:"nickname" description:"用户昵称（前端授权后传入）"`
+	AvatarURL  string `json:"avatar_url" description:"用户头像URL（前端授权后传入）"`
+}
+
+// ========================================
+// A4 发送验证码
+// ========================================
+
+// ClientSendCodeRequest A4 发送验证码请求
+type ClientSendCodeRequest struct {
+	Phone string `json:"phone" validate:"required,len=11" required:"true" minLength:"11" maxLength:"11" description:"手机号"`
+	Scene string `json:"scene" validate:"required,oneof=bind_phone change_phone_old change_phone_new" required:"true" description:"业务场景 (bind_phone:绑定手机号, change_phone_old:换绑旧手机, change_phone_new:换绑新手机)"`
+}
+
+// ClientSendCodeResponse A4 发送验证码响应
+type ClientSendCodeResponse struct {
+	CooldownSeconds int `json:"cooldown_seconds" description:"冷却秒数"`
+}
+
+// ========================================
+// A5 绑定手机号
+// ========================================
+
+// BindPhoneRequest A5 绑定手机号请求
+type BindPhoneRequest struct {
+	Phone string `json:"phone" validate:"required,len=11" required:"true" minLength:"11" maxLength:"11" description:"手机号"`
+	Code  string `json:"code" validate:"required,len=6" required:"true" minLength:"6" maxLength:"6" description:"验证码"`
+}
+
+// BindPhoneResponse A5 绑定手机号响应
+type BindPhoneResponse struct {
+	Phone   string `json:"phone" description:"已绑定手机号"`
+	BoundAt string `json:"bound_at" description:"绑定时间"`
+}
+
+// ========================================
+// A6 换绑手机号
+// ========================================
+
+// ChangePhoneRequest A6 换绑手机号请求
+type ChangePhoneRequest struct {
+	OldPhone string `json:"old_phone" validate:"required,len=11" required:"true" minLength:"11" maxLength:"11" description:"旧手机号"`
+	OldCode  string `json:"old_code" validate:"required,len=6" required:"true" minLength:"6" maxLength:"6" description:"旧手机号验证码"`
+	NewPhone string `json:"new_phone" validate:"required,len=11" required:"true" minLength:"11" maxLength:"11" description:"新手机号"`
+	NewCode  string `json:"new_code" validate:"required,len=6" required:"true" minLength:"6" maxLength:"6" description:"新手机号验证码"`
+}
+
+// ChangePhoneResponse A6 换绑手机号响应
+type ChangePhoneResponse struct {
+	Phone     string `json:"phone" description:"换绑后手机号"`
+	ChangedAt string `json:"changed_at" description:"换绑时间"`
+}
+
+// ========================================
+// A7 退出登录
+// ========================================
+
+// LogoutResponse A7 退出登录响应
+type LogoutResponse struct {
+	Success bool `json:"success" description:"是否成功"`
+}

internal/model/personal_customer_openid.go

@@ -0,0 +1,23 @@
+package model
+
+import (
+	"gorm.io/gorm"
+)
+
+// PersonalCustomerOpenID 个人客户 OpenID 关联模型
+// 保存客户在不同微信应用（公众号/小程序）下的 OpenID 记录
+// 同一客户可在多个 AppID 下拥有不同的 OpenID
+// 唯一约束：UNIQUE(app_id, open_id) WHERE deleted_at IS NULL
+type PersonalCustomerOpenID struct {
+	gorm.Model
+	CustomerID uint   `gorm:"column:customer_id;type:bigint;not null;index:idx_pco_customer_id;comment:关联个人客户ID" json:"customer_id"`
+	AppID      string `gorm:"column:app_id;type:varchar(100);not null;comment:微信应用标识（公众号或小程序AppID）" json:"app_id"`
+	OpenID     string `gorm:"column:open_id;type:varchar(100);not null;comment:当前应用下的OpenID" json:"open_id"`
+	UnionID    string `gorm:"column:union_id;type:varchar(100);not null;default:'';comment:微信开放平台统一标识（可选）" json:"union_id"`
+	AppType    string `gorm:"column:app_type;type:varchar(20);not null;default:'';comment:应用类型（official_account/miniapp）" json:"app_type"`
+}
+
+// TableName 指定表名
+func (PersonalCustomerOpenID) TableName() string {
+	return "tb_personal_customer_openid"
+}