feat(server): 归因v2——paid_social渠道与fb+付费medium优先规则

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

server/tracker/tests/test_attribution.py

@@ -69,7 +69,7 @@ def test_paid_click_param_wins_over_natural_search():
     assert r["channel"] == "paid_search" and r["platform"] == "Google Ads"   # 付费优先于自然
     assert r["detail"].get("click_param") == "gclid"
     r2 = classify(landing_path="/?fbclid=IwAR0")                            # 仅落地页带点击参数
-    assert r2["channel"] == "paid_search" and r2["platform"] == "Meta Ads"
+    assert r2["channel"] == "paid_social" and r2["platform"] == "Meta Ads"  # v2：fbclid → 付费社交
 
 
 def test_paid_param_in_referrer_url():
@@ -148,13 +148,14 @@ def test_utm_chinese_alias_baidu_matches():
 # ------------------------------------------- 广告家族归一（付费点击参数 ↔ UTM 同家族）
 def test_fbclid_with_utm_fb_same_meta_family_combined():
     r = classify(landing_path="/?fbclid=IwAR0", utm={"utm_source": "fb"})
-    assert r["channel"] == "paid_search" and r["platform"] == "Meta Ads"
+    assert r["channel"] == "paid_social" and r["platform"] == "Meta Ads"    # v2：fbclid → 付费社交
     assert r["resolution"] == "resolved" and r["evidence_kind"] == "combined"
     assert r["detail"].get("utm_source") == "fb"       # fb ↔ Meta Ads 同 meta 家族
 
 
 def test_fbclid_with_utm_ig_combined():
     r = classify(landing_path="/?fbclid=IwAR0", utm={"utm_source": "ig"})
+    assert r["channel"] == "paid_social"
     assert r["platform"] == "Meta Ads"                 # ig 也在 meta 家族
     assert r["resolution"] != "conflict" and r["evidence_kind"] == "combined"
 
@@ -202,6 +203,44 @@ def test_garbage_referrer_url_does_not_crash():
     assert r["channel"] in ("referral", "direct")   # 不崩，落到兜底分支即可
 
 
+# ---------------------------------------- paid_social 渠道（归因 v2，spec §3）
+def test_fb_paid_medium_priority():
+    # 实测主导模式：utm_medium=paid&utm_source=fb → paid_social（优先于强化集）
+    r = classify(referrer_url="", utm={"utm_source": "fb", "utm_medium": "paid"},
+                 landing_path="/", ua="", internal_domains=[])
+    assert r["channel"] == "paid_social"
+
+
+def test_fb_family_medium_union():
+    for m in ("cpc", "social", "paid_social", "social_ads"):
+        r = classify(referrer_url="", utm={"utm_source": "facebook.com", "utm_medium": m},
+                     landing_path="/", ua="", internal_domains=[])
+        assert r["channel"] == "paid_social", m
+
+
+def test_nonfb_paid_medium_stays_paid_search_label_only():
+    r = classify(referrer_url="", utm={"utm_source": "google", "utm_medium": "cpc"},
+                 landing_path="/", ua="", internal_domains=[])
+    assert r["channel"] == "paid_search" and r["resolution"] == "label_only"
+
+
+def test_fbclid_now_paid_social():
+    r = classify(referrer_url="", utm={}, landing_path="/?fbclid=IwARxyz", ua="", internal_domains=[])
+    assert r["channel"] == "paid_social"
+
+
+def test_gclid_still_paid_search():
+    r = classify(referrer_url="", utm={}, landing_path="/?gclid=EAIa", ua="", internal_domains=[])
+    assert r["channel"] == "paid_search"
+
+
+def test_nonfb_social_medium_not_paid():
+    # twitter&utm_medium=social → 不判付费（有意分歧：防误伤自然社交）
+    r = classify(referrer_url="", utm={"utm_source": "twitter", "utm_medium": "social"},
+                 landing_path="/", ua="", internal_domains=[])
+    assert r["channel"] != "paid_search" and r["channel"] != "paid_social"
+
+
 # ------------------------------------------------------- 入库 + 重算集成
 @pytest.mark.django_db
 def test_ingest_writes_first_touch_and_session_entry():
@@ -216,7 +255,7 @@ def test_ingest_writes_first_touch_and_session_entry():
     ft = SourceClassification.objects.get(site=site, visitor__visitor_id="v1", scope="first_touch")
     assert ft.session is None
     assert ft.channel == "natural_search" and ft.platform == "Bing"
-    assert ft.search_term == "挖掘机" and ft.rule_version == "v1"
+    assert ft.search_term == "挖掘机" and ft.rule_version == "v2"
     se = SourceClassification.objects.get(site=site, scope="session_entry")
     assert se.session.session_id == "s1"
     assert se.channel == "natural_search" and se.platform == "Bing"