feat(auth): 用户账户 - 完善个人资料与登录日志 (#752)

Co-authored-by: wuligao <1247662379@qq.com>

backend/internal/model/models_user_avatar.go

@@ -0,0 +1,10 @@
+package model
+
+import "time"
+
+// UserAvatar keeps the bounded image payload out of ordinary user queries.
+type UserAvatar struct {
+	UserID    string    `gorm:"primaryKey;size:36" json:"userId"`
+	Data      []byte    `gorm:"not null" json:"-"`
+	UpdatedAt time.Time `json:"updatedAt"`
+}