feat: 实现域能系统

- 新增域能完整分层：EnergyLog/PostEnergizeLog/DailyExpSummary 模型、EnergyRepo、EnergyService、EnergyController/AdminEnergyController
- 支持签到获取域能(+1)、帖子赋能(-1/-2)/被赋能(+1/+2)、改名扣能(-6)/退款(+6)、删帖扣能(-2)
- 赋能单人单帖上限20域能，每日赋能获得经验上限50
- 管理员支持批量调整域能(owner)和查询域能日志(admin)
- LV0用户(exp<1)禁止签到和发帖，余额为负可签到/被赋能/删帖但不能赋能/改名
- 首次改名免费(通过HasCompletedTask判重)，改名扣能在提交审核时执行
- 移除导航栏手动签到按钮，签到融入域能系统(自动签到)
- 新增个人中心域能TAB展示余额和流水日志(近7天)
- 新增帖子详情页赋能按钮(轻赋/重赋)
- 管理后台新增域能管理和域能日志页面

internal/model/energy_log.go

@@ -0,0 +1,38 @@
+package model
+
+import "time"
+
+// 域能流水类型常量
+const (
+	EnergyTypeSignIn      = "sign_in"
+	EnergyTypeRename      = "rename"
+	EnergyTypeRenameRefund = "rename_refund"
+	EnergyTypeEnergize    = "energize"
+	EnergyTypeEnergized   = "energized"
+	EnergyTypeDeletePost  = "delete_post"
+	EnergyTypeAdminAdjust = "admin_adjust"
+)
+
+// EnergyLog 域能流水记录
+type EnergyLog struct {
+	ID          uint      `gorm:"primarykey" json:"id"`
+	UserID      uint      `gorm:"index;not null" json:"user_id"`
+	Amount      int       `gorm:"not null" json:"amount"`                   // 变化量（乘10，正为增加，负为扣减）
+	Type        string    `gorm:"type:varchar(30);index;not null" json:"type"` // sign_in/rename/rename_refund/energize/energized/delete_post/admin_adjust
+	RelatedType string    `gorm:"type:varchar(30);default:''" json:"related_type,omitempty"`
+	RelatedID   uint      `gorm:"default:0" json:"related_id,omitempty"`
+	Description string    `gorm:"type:varchar(500);default:''" json:"description,omitempty"`
+	OperatorUID *uint     `gorm:"default:null" json:"operator_uid,omitempty"` // 操作者UID（后台操作时必填）
+	CreatedAt   time.Time `json:"created_at"`
+}
+
+// EnergyLogDisplayNames 流水类型 → 中文名
+var EnergyLogDisplayNames = map[string]string{
+	EnergyTypeSignIn:      "每日签到",
+	EnergyTypeRename:      "改名消耗",
+	EnergyTypeRenameRefund: "改名退款",
+	EnergyTypeEnergize:    "赋能消耗",
+	EnergyTypeEnergized:   "被赋能",
+	EnergyTypeDeletePost:  "删稿消耗",
+	EnergyTypeAdminAdjust: "后台调整",
+}