feat: 实现PIPL数据主体删除权支持功能

- 新增 LeadDeletionRequest 模型，支持邮箱验证的删除申请/确认流程
- POST /api/v1/custom/leads/deletion-requests/ 发起申请（通用响应避免探测邮箱是否存在）
- POST /api/v1/custom/leads/deletion-requests/confirm/ 确认删除（24小时token有效期）
- 按邮箱在 Lead.data 中匹配并删除对应记录，跨SQLite/Postgres使用Python级匹配
- LeadDeletionRequest 通过 Django Admin 只读展示供合规审计
- 新增 FRONTEND_BASE_URL 设置用于拼接邮件确认链接
- apps/forms/tests.py 新增6个测试用例（含节流缓存隔离修复），全仓库30个用例通过
- 更新设计文档 §2.15/§2.16 勾选项

apps/forms/tests.py

@@ -1,12 +1,28 @@
 """apps.forms 单元测试：线索提交 API（B2B 官网核心转化路径，测试覆盖率要求较高）。"""
+from datetime import timedelta
+
 import pytest
+from django.core.cache import cache
+from django.utils import timezone
 from rest_framework.test import APIClient
 
-from apps.forms.models import FormDefinition, FormDefinitionField, Lead
+from apps.forms.models import (
+    FormDefinition,
+    FormDefinitionField,
+    Lead,
+    LeadDeletionRequest,
+)
 
 pytestmark = pytest.mark.django_db
 
 
+@pytest.fixture(autouse=True)
+def _clear_throttle_cache():
+    """ScopedRateThrottle 依赖默认缓存记录请求次数，避免测试间相互影响（forms scope 限流 5/min）。"""
+    cache.clear()
+    yield
+
+
 @pytest.fixture
 def contact_form():
     form_def = FormDefinition.objects.create(
@@ -62,3 +78,124 @@ def test_lead_submit_requires_form_id():
     )
 
     assert response.status_code == 400
+
+
+# --- PIPL 数据删除权（详见设计文档 §2.15） ---
+
+
+def test_deletion_request_returns_generic_message_and_sends_email(
+    contact_form, mailoutbox
+):
+    Lead.objects.create(
+        form=contact_form,
+        data={"name": "张三", "email": "zhangsan@example.com"},
+    )
+
+    client = APIClient()
+    response = client.post(
+        "/api/v1/custom/leads/deletion-requests/",
+        {"contact": "zhangsan@example.com"},
+        format="json",
+    )
+
+    assert response.status_code == 202
+    assert LeadDeletionRequest.objects.filter(contact="zhangsan@example.com").exists()
+    assert len(mailoutbox) == 1
+    assert mailoutbox[0].to == ["zhangsan@example.com"]
+
+
+def test_deletion_request_returns_same_generic_message_for_unknown_contact(mailoutbox):
+    """未提交过表单的邮箱也返回相同提示，避免探测。"""
+    client = APIClient()
+    response_known = client.post(
+        "/api/v1/custom/leads/deletion-requests/",
+        {"contact": "known@example.com"},
+        format="json",
+    )
+    response_unknown = client.post(
+        "/api/v1/custom/leads/deletion-requests/",
+        {"contact": "unknown@example.com"},
+        format="json",
+    )
+
+    assert response_known.status_code == response_unknown.status_code == 202
+    assert response_known.data["message"] == response_unknown.data["message"]
+
+
+def test_deletion_confirm_deletes_matching_leads_only(contact_form):
+    matching_lead = Lead.objects.create(
+        form=contact_form,
+        data={"name": "张三", "email": "zhangsan@example.com"},
+    )
+    other_lead = Lead.objects.create(
+        form=contact_form,
+        data={"name": "李四", "email": "lisi@example.com"},
+    )
+    deletion_request = LeadDeletionRequest.objects.create(contact="zhangsan@example.com")
+
+    client = APIClient()
+    response = client.post(
+        "/api/v1/custom/leads/deletion-requests/confirm/",
+        {"token": str(deletion_request.token)},
+        format="json",
+    )
+
+    assert response.status_code == 200
+    assert response.data["success"] is True
+    assert response.data["deleted_count"] == 1
+    assert not Lead.objects.filter(pk=matching_lead.pk).exists()
+    assert Lead.objects.filter(pk=other_lead.pk).exists()
+
+    deletion_request.refresh_from_db()
+    assert deletion_request.status == LeadDeletionRequest.STATUS_COMPLETED
+    assert deletion_request.deleted_count == 1
+    assert deletion_request.completed_at is not None
+
+
+def test_deletion_confirm_invalid_token_returns_404():
+    client = APIClient()
+    response = client.post(
+        "/api/v1/custom/leads/deletion-requests/confirm/",
+        {"token": "00000000-0000-0000-0000-000000000000"},
+        format="json",
+    )
+
+    assert response.status_code == 404
+    assert response.data["error"]["code"] == "INVALID_TOKEN"
+
+
+def test_deletion_confirm_expired_token_returns_400():
+    deletion_request = LeadDeletionRequest.objects.create(contact="zhangsan@example.com")
+    LeadDeletionRequest.objects.filter(pk=deletion_request.pk).update(
+        requested_at=timezone.now() - timedelta(hours=25)
+    )
+
+    client = APIClient()
+    response = client.post(
+        "/api/v1/custom/leads/deletion-requests/confirm/",
+        {"token": str(deletion_request.token)},
+        format="json",
+    )
+
+    assert response.status_code == 400
+    assert response.data["error"]["code"] == "TOKEN_EXPIRED"
+
+    deletion_request.refresh_from_db()
+    assert deletion_request.status == LeadDeletionRequest.STATUS_EXPIRED
+
+
+def test_deletion_confirm_already_processed_returns_400():
+    deletion_request = LeadDeletionRequest.objects.create(
+        contact="zhangsan@example.com",
+        status=LeadDeletionRequest.STATUS_COMPLETED,
+    )
+
+    client = APIClient()
+    response = client.post(
+        "/api/v1/custom/leads/deletion-requests/confirm/",
+        {"token": str(deletion_request.token)},
+        format="json",
+    )
+
+    assert response.status_code == 400
+    assert response.data["error"]["code"] == "ALREADY_PROCESSED"