feat(billing): 计费商业化重构(积分制)+ 团队差异化调价

统一计价引擎 apps/billing/pricing.py:1积分=¥0.1,平台成本(¥)与用户价(积分)双记账,
视频按火山真实 usage.total_tokens 结算(true-up,终结¥1/段倒贴)+ 首发×1.5毛利系数。
Team.price_multiplier 差异化调价(jimeng同款):挂牌价×系数两步HALF_UP取整,视频类
按下单时的价格/汇率快照结算(中途改配不影响在途任务)。

BillingConfig 单例(汇率/毛利系数/预留buffer,admin可调即刻生效)。存量数据 ×10 rescale
迁移(RunPython+atomic,MySQL 迁移不可中断重跑)。开户赠送归零(DEFAULT_TRIAL_CREDITS=0,
商业决策)。audit_billing 加 I9(卖亏审计)。271 条测试 + tsc/build 全绿。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

core/backend/apps/adminpanel/serializers.py

@@ -75,7 +75,7 @@ class AdminTeamSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Team
-        fields = ["id", "name", "status", "owner", "owner_username", "member_count", "balance", "created_at"]
+        fields = ["id", "name", "status", "owner", "owner_username", "member_count", "balance", "price_multiplier", "created_at"]
         read_only_fields = fields
 
     def get_member_count(self, obj):
@@ -116,18 +116,38 @@ class AdminTaskSerializer(serializers.ModelSerializer):
     team_name = serializers.CharField(source="team.name", read_only=True, default=None)
     model_name = serializers.CharField(source="model_config.name", read_only=True, default=None)
     cost_anomaly = serializers.SerializerMethodField()
+    # 单任务毛利(¥):actual_cost(积分)÷汇率 − base_cost。base_cost=0(成本未知)时 None,报表侧过滤
+    margin_yuan = serializers.SerializerMethodField()
 
     class Meta:
         model = AITask
         fields = [
             "id", "task_type", "status", "team", "team_name", "model_name",
-            "estimated_cost", "actual_cost", "cost_anomaly", "error_code", "created_at",
+            "estimated_cost", "actual_cost", "base_cost", "margin_yuan", "cost_anomaly", "error_code", "created_at",
         ]
         read_only_fields = fields
 
     def get_cost_anomaly(self, obj) -> bool:
         return is_cost_anomaly(obj.estimated_cost, obj.actual_cost)
 
+    def get_margin_yuan(self, obj) -> str | None:
+        base = obj.base_cost or Decimal("0")
+        actual = obj.actual_cost or Decimal("0")
+        if base <= 0 or actual <= 0:
+            return None
+        from apps.billing.pricing import get_billing_config
+
+        # 优先用任务计价当时的汇率快照:汇率调整不追溯历史,毛利报表不整体漂移(review 确认)。
+        # __dict__ 直取避免触发 deferred 列加载(有的列表 queryset 会 defer payload)。
+        payload = obj.__dict__.get("request_payload") or {}
+        try:
+            rate = Decimal(str(payload.get("points_per_yuan_snapshot") or "")) if payload.get("points_per_yuan_snapshot") else get_billing_config().points_per_yuan
+        except Exception:  # noqa: BLE001
+            rate = get_billing_config().points_per_yuan
+        if rate <= 0:
+            return None
+        return str((actual / rate - base).quantize(Decimal("0.01")))
+
 
 class AdminTaskDetailSerializer(AdminTaskSerializer):
     class Meta(AdminTaskSerializer.Meta):