fix: ingest 落库 SDK timezone 到 Visitor.timezone_name（Task16 联调发现）

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

server/tracker/services/ingest.py

@@ -42,6 +42,9 @@ def _geo_field(g, key):
 
 def _touch_visitor(site, vid, ctx, ip):
     env = {k: str(ctx.get(k, "") or "")[:n] for k, n in _FIELD_LEN.items()}
+    # Task16 联调发现：键名映射缺口——SDK context 发 "timezone"，模型字段是 timezone_name，
+    # 同名推导的 _FIELD_LEN 取不到值，导致 timezone_name 恒空。
+    env["timezone_name"] = str(ctx.get("timezone", "") or "")[:64]
     v, created = Visitor.objects.get_or_create(
         site=site, visitor_id=vid, defaults={**env, "last_ip": ip})
     now = timezone.now()

server/tracker/tests/test_ingest.py

@@ -134,3 +134,11 @@ def test_missing_payload_fields_rejected(db):
     p = _batch([_ev(1)])
     del p["session_id"]
     assert ingest_batch(site, p)["rejected"] == [{"reason": "invalid_payload"}]
+
+# 14. SDK context 的 timezone 落库 Visitor.timezone_name（Task16 联调发现：键名映射缺口）
+def test_context_timezone_persisted_to_visitor(db):
+    site = Site.objects.create(name="s", domains=["a.com"])
+    b = _batch([_ev(1)])
+    b["context"]["timezone"] = "Asia/Shanghai"
+    ingest_batch(site, b)
+    assert Visitor.objects.get(visitor_id="v1").timezone_name == "Asia/Shanghai"