新功能(#3): 抽奖 Stage 1 handler 真实业务对接 + 邀请钩子

Closes HIF-3 (阶段 PR B)

PR B：handler 真实业务对接 + 邀请钩子（迭代含 R1 修复）

- 迁移 02157_lottery_grant_ledger：external_ref UNIQUE 作为发奖幂等键
- log.CommissionTypeLottery=339（架构师批准的新常量）
- DispatchRequest.IdempotencyKey（架构师 review 建议第 2 条）
- GrantLedger + LedgerService.Reserve：INSERT ON CONFLICT DO NOTHING 幂等 upsert
- VPNDurationHandler：ResolveEffectiveUser 归位家庭 owner + UpdateSubscribe，ExpireTime 三分支对齐 grantGiftDays
- CommissionHandler：UpdateCommission + WriteCommissionLog(339)，发给中奖者本人，不做家庭组归位
- Handler 从 model 层迁到 logic 层（避免 model → logic 反向依赖）；noop 保留在 model 层
- InviteHook：fire-and-forget 独立 goroutine + 10s timeout，扫 running 活动的 invite_success 源
- ServiceContext 新增 LotteryChance / LotteryLedger / LotteryInviteHook
- activateOrderLogic.handleCommission 两条分支通过 invokeInviteHookIfEligible 助手触发，助手内统一 gate IsNew（架构师 R1 打回后的修复）

架构师 R1 打回：branch B 未按"首次付款激活"gate，续费也会给 referer 发抽奖机会 → 已通过助手函数集中收拢，避免 branch A/B 判断漂移。

测试覆盖率：model 76.5% / handler 73.2% / hook 91.7%；补 4 个回归测试覆盖 IsNew 门槛（含关键的 DoesNotFireOnRenewal）。

线上仍零可见变更：无对外路由，钩子仅在活动 status=running 时生效，Stage 1 全流程无活动记录时 loadRunningActivities 返回空。

internal/svc/serviceContext.go

@@ -11,6 +11,7 @@ import (
 	"github.com/perfect-panel/server/pkg/storage"
 
 	"github.com/perfect-panel/server/internal/config"
+	lotteryhook "github.com/perfect-panel/server/internal/logic/lottery/hook"
 	"github.com/perfect-panel/server/internal/model/ads"
 	"github.com/perfect-panel/server/internal/model/announcement"
 	"github.com/perfect-panel/server/internal/model/auth"
@@ -19,6 +20,7 @@ import (
 	iapapple "github.com/perfect-panel/server/internal/model/iap/apple"
 	"github.com/perfect-panel/server/internal/model/log"
 	logmessage "github.com/perfect-panel/server/internal/model/logmessage"
+	"github.com/perfect-panel/server/internal/model/lottery"
 	"github.com/perfect-panel/server/internal/model/order"
 	"github.com/perfect-panel/server/internal/model/payment"
 	"github.com/perfect-panel/server/internal/model/promo"
@@ -71,6 +73,11 @@ type ServiceContext struct {
 	AnnouncementModel        announcement.Model
 	IAPAppleTransactionModel iapapple.Model
 
+	// Lottery (Stage 1)
+	LotteryChance     lottery.ChanceService
+	LotteryLedger     lottery.LedgerService
+	LotteryInviteHook lotteryhook.InviteHook
+
 	Restart               func() error
 	TelegramBot           *tgbotapi.BotAPI
 	NodeMultiplierManager *nodeMultiplier.Manager
@@ -148,6 +155,11 @@ func NewServiceContext(c config.Config) *ServiceContext {
 	}
 	srv.IAPAppleTransactionModel = iapapple.NewModel(db, rds)
 	srv.DeviceManager = NewDeviceManager(srv)
+	// Lottery Stage 1: wire the always-safe pieces (ChanceService, LedgerService,
+	// InviteHook). PrizeHandler registry is created in the draw service (PR C).
+	srv.LotteryChance = lottery.NewChanceService(db)
+	srv.LotteryLedger = lottery.NewLedgerService()
+	srv.LotteryInviteHook = lotteryhook.NewInviteHook(db, srv.LotteryChance)
 	if c.S3.Enable {
 		s3Store, err := storage.NewS3Store(context.Background(), c.S3)
 		if err != nil {