feat(distribution): 移除生产环境资金冻结，测试与生产口径统一

liveMoneyMovementEnabled 按 APP_ENV 在生产冻结结算入账、站点提现与自动释放，
与测试环境行为不一致，且该开关在 APP_ENV 缺失时为 fail-open。本次整体移除：

- 删除 liveMoneyMovementEnabled 与 ErrLiveMoneyMovementFrozen
- MarkSettlementBatch / ApplySiteWithdrawal / AutoReleaseDueSettlements 去掉守卫
- handler 去掉 403 settlement_frozen 映射
- 测试改为断言生产环境结算入账与提现正常执行

backend/internal/modules/distribution/repository.go

@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"os"
 	"strings"
 	"time"
 
@@ -41,7 +40,6 @@ var (
 	ErrAdminDisabled             = errors.New("admin disabled")
 	ErrDuplicateSiteCodeOrDomain = errors.New("distribution site code or domain already exists")
 	ErrDuplicateUsername         = errors.New("username already exists")
-	ErrLiveMoneyMovementFrozen   = errors.New("distribution settlement and withdrawal frozen until split rules are verified")
 	ErrTooManySyncListings       = errors.New("too many listings to sync")
 	ErrSyncListingNotFound       = errors.New("sync listing not found")
 	ErrEmptyListingIDs           = errors.New("listing ids required")
@@ -54,11 +52,6 @@ var settlementReadyOrderStatuses = []string{"completed", "closed"}
 
 const maxSyncListingIDs = 200
 
-func liveMoneyMovementEnabled() bool {
-	env := strings.ToLower(strings.TrimSpace(os.Getenv("APP_ENV")))
-	return env != "production" && env != "prod"
-}
-
 // normalizeSettlementHoldDays 校验站点结算冷却天数，允许 0（订单完成即释放）到 365 天。
 func normalizeSettlementHoldDays(days int) (int, error) {
 	if days < 0 || days > 365 {
@@ -1021,9 +1014,6 @@ func (r *Repository) CreateSettlementBatch(ctx context.Context, adminID uint64,
 }
 
 func (r *Repository) MarkSettlementBatch(ctx context.Context, adminID, id uint64) (*SettlementBatchDTO, error) {
-	if !liveMoneyMovementEnabled() {
-		return nil, ErrLiveMoneyMovementFrozen
-	}
 	var row model.DistributionSettlementBatch
 	err := r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).First(&row, id).Error; err != nil {
@@ -2056,9 +2046,6 @@ func (r *Repository) GetSiteWallet(ctx context.Context, adminID, siteID uint64)
 }
 
 func (r *Repository) ApplySiteWithdrawal(ctx context.Context, adminID, siteID uint64, req ApplySiteWithdrawalRequest) (*SiteWithdrawalDTO, error) {
-	if !liveMoneyMovementEnabled() {
-		return nil, ErrLiveMoneyMovementFrozen
-	}
 	if siteID == 0 {
 		return nil, ErrSiteNotFound
 	}