feat(admin): Phase 3 平台团队+用户管理 — 列/启停/详情/强制改密 + 团队停用拦登录

后端:adminpanel 增 teams(列/详情/启停)+ users(列/启停/强制改密),AdminTeam/User 序列化器;
login 校验团队 status,停用团队成员拒登;停用用户清 token、禁停平台超管;全程 IsPlatformAdmin + 审计。
前端:adminApi teams/users 系列;Admin 团队页(筛选+搜索+详情弹窗+启停)、用户页(启停+改密弹窗,超管行禁操作)。
测试:adminpanel 19 + accounts 22 = 41 单测过;无头 e2e _admin-p3.mjs 7 断言过 + 0 console error
(UI 停用团队→成员登录 400→启用→200;UI 改密→新密码登录 200);tsc+build 绿。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/backend/apps/adminpanel/serializers.py

@@ -0,0 +1,47 @@
+from rest_framework import serializers
+
+from apps.accounts.models import Team, TeamMember, User
+
+
+class AdminTeamSerializer(serializers.ModelSerializer):
+    owner_username = serializers.CharField(source="owner.username", read_only=True, default=None)
+    member_count = serializers.SerializerMethodField()
+    balance = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Team
+        fields = ["id", "name", "status", "owner", "owner_username", "member_count", "balance", "created_at"]
+        read_only_fields = fields
+
+    def get_member_count(self, obj):
+        anno = getattr(obj, "member_count_anno", None)
+        return anno if anno is not None else obj.members.count()
+
+    def get_balance(self, obj):
+        acct = getattr(obj, "credit_account", None)
+        return str(acct.balance) if acct is not None else "0"
+
+
+class AdminTeamMemberSerializer(serializers.ModelSerializer):
+    username = serializers.CharField(source="user.username", read_only=True)
+    user_status = serializers.CharField(source="user.status", read_only=True)
+
+    class Meta:
+        model = TeamMember
+        fields = ["id", "username", "role", "status", "user_status", "monthly_credit_limit"]
+        read_only_fields = fields
+
+
+class AdminUserSerializer(serializers.ModelSerializer):
+    teams = serializers.SerializerMethodField()
+
+    class Meta:
+        model = User
+        fields = ["id", "username", "status", "is_platform_admin", "date_joined", "teams"]
+        read_only_fields = fields
+
+    def get_teams(self, obj):
+        return [
+            {"team_id": str(m.team_id), "team_name": m.team.name, "role": m.role}
+            for m in obj.team_memberships.select_related("team").all()
+        ]