fix(server): v2入口加固——page_id孤代理/NaN区间值拒绝，共享ISO解析

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

server/tracker/services/ingest.py

@@ -23,7 +23,8 @@ page_id），会话按事件级 session_id 解析（v1 信封不再是唯一依
 （v2 附注：stay_ms 重算对"并发同会话双批"同样存在同类窗口——后提交者的 SELECT 可能
 看不到前者未提交事件而少算，与 TOCTOU 同级、只影响 stay_ms 单字段。）
 """
-from datetime import datetime, timedelta, timezone as dt_tz
+from datetime import timedelta
+import math
 
 from django.db import transaction, IntegrityError
 from django.db.models import F, Q
@@ -32,31 +33,25 @@ from django.utils import timezone
 
 from tracker import constants as C
 from tracker.models import SourceClassification, Visitor, VisitSession, Event
-from tracker.services.validation import validate_event
+from tracker.services.validation import validate_event, parse_iso_dt
 from tracker.services.attribution import classify
 from tracker.services.geo import resolver as _geo   # 模块级单例（勿实例化，11MB/份）
 
 _FIELD_LEN = {"device_type": 16, "os": 64, "browser": 64, "language": 32, "screen": 32}
 _CLASS_FIELDS = ("channel", "platform", "variant", "search_term",
                  "evidence_kind", "resolution", "detail")
-
-
-def _occ_dt(v):
-    """v2 事件 occurred_at 允许 ISO 字符串（SDK 线格式；collect 视图已预转 datetime，
-    直连调用方可能传原文）。解析失败抛 ValueError/TypeError——调用方放行原值，
-    由 validate_event 统一拒 invalid_occurred_at。naive 视为 UTC（与 collect._iso 同口径）。"""
-    if isinstance(v, str):
-        d = datetime.fromisoformat(v.replace("Z", "+00:00"))
-        return d if d.tzinfo else d.replace(tzinfo=dt_tz.utc)
-    return v
+_BIGINT_MAX = 2 ** 63 - 1   # BigIntegerField 8 字节量纲上限——超范围值炸列，按 None 降级
 
 
 def _ms(v):
-    """v2 区间字段宽松 int 化：bool/非数值 → None（脏数据防御——recompute 会过滤 None 区间，
-    该事件不参与并集但不拒批）。"""
+    """v2 区间字段宽松 int 化，任何脏值一律 None（recompute 过滤 None 区间，不拒批）：
+    bool/非数值；NaN/Infinity（json.loads 默认收这两个字面量，int() 抛 ValueError/
+    OverflowError）；超 BigIntegerField 量纲的有限值（DB 写入炸列）。"""
     if isinstance(v, bool) or not isinstance(v, (int, float)):
         return None
-    return int(v)
+    if not math.isfinite(v):
+        return None
+    return int(v) if -_BIGINT_MAX <= v <= _BIGINT_MAX else None
 
 
 def _time_quality(now, occ) -> str:
@@ -284,7 +279,7 @@ def ingest_batch(site, payload: dict, ip: str | None = None, ua: str = "") -> di
     for i, ev in enumerate(events):
         if v2 and isinstance(ev, dict) and isinstance(ev.get("occurred_at"), str):
             try:    # v2 事件 occurred_at 允许 ISO 字符串（SDK 线格式）；解析失败放行原值，
-                ev["occurred_at"] = _occ_dt(ev["occurred_at"])   # validate_event 统一拒 invalid_occurred_at
+                ev["occurred_at"] = parse_iso_dt(ev["occurred_at"])   # validate_event 统一拒 invalid_occurred_at
             except (ValueError, TypeError):
                 pass
         reason = validate_event(ev, v2=v2, batch_site_id=site.site_id,