refactor(time): 时间列统一走 UTCDateTime，并把 MySQL 会话时区对齐成 UTC

问题不是「UTC 还是本地时间」，而是这套口径有两个半吊子的地方：

1. 库里存 naive UTC、读出来也是裸时间，于是每一处比较/输出都得自己补时区。
   项目里因此散了三份 _as_utc 和一堆 replace(tzinfo=UTC)，P1a 排下一轮时间
   时还炸过一次 TypeError: can't compare offset-naive and offset-aware。
2. MySQL 会话时区跟随系统 +08:00，而库里存的是 UTC —— SQL 里的 NOW()/
   CURDATE() 比库里的时间快 8 小时，查询会静默返回空（P1a 排查时就遇到过，
   看着像「没有数据」）。

改动：

- 新增 database.UTCDateTime：写时 aware→转 UTC 去 tzinfo、naive 视为 UTC；
  读时一律补 UTC 时区。底层 DDL 仍是 DATETIME，**不需要迁移**。models.py 的
  28 个时间列全部改用它，模型上的时间字段从此不再是裸值；
- docker-compose 给 mysql 加 --default-time-zone=+00:00，让 SQL 时间函数与存储
  口径一致。安全性已核实：全库 0 个 TIMESTAMP 列、0 个 CURRENT_TIMESTAMP
  默认值，改这里不会改变任何已有数据的语义；
- 新增 tests/test_utc_datetime.py：读出必须 aware、能直接和 datetime.now(UTC)
  比较、带 +08:00 的写入要落成 UTC、naive 写入视为 UTC，并有一条元测试扫描
  Base.metadata，防止以后新增时间列忘了用 UTCDateTime。

保留既有的 _as_utc 补丁（对 aware 值是幂等的，属防御性代码）；新代码不再需要。
「存 UTC、算 UTC、显示本地」三条线至此各自明确：存储与比较统一 UTC，日志按
容器 TZ 显示本地时间，前端 formatTime 负责转本地。

docker-compose.yml

@@ -122,6 +122,12 @@ services:
     command:
       - --character-set-server=utf8mb4
       - --collation-server=utf8mb4_0900_ai_ci
+      # 会话时区与存储口径对齐：库里所有时间列存的都是 UTC（应用一律写
+      # datetime.now(UTC)，MySQL 绑定参数丢掉 tzinfo 后落库即 UTC 裸值）。
+      # 若仍跟随系统 +08:00，SQL 里的 NOW()/CURDATE() 会比库里时间快 8 小时，
+      # 查询静默返回空、看着像「没数据」。全库无 TIMESTAMP 列、也没有
+      # CURRENT_TIMESTAMP 默认值，因此改这里不会改变任何已有数据的语义。
+      - --default-time-zone=+00:00
       # 业务表已超过 300MiB；可通过 .env 调整，默认给 MySQL 512MiB 缓冲池。
       - --innodb-buffer-pool-size=${MYSQL_INNODB_BUFFER_POOL_SIZE:-512M}
       # 默认记录 1 秒以上查询，便于验证查询优化；稳定后可设 MYSQL_SLOW_QUERY_LOG=0。

tests/test_huya_sms_url.py

@@ -156,4 +156,4 @@ def test_solver_sms_flow():
         mock_submit.assert_called_once()
         verify_url, verify_payload = mock_submit.call_args[0]
         assert "verify-sms-code" in verify_url
-        assert verify_payload["data"]["smsCode"] == "654321".encode().hex()
+        assert verify_payload["data"]["smsCode"] == b"654321".hex()

tests/test_utc_datetime.py

@@ -0,0 +1,94 @@
+"""回归：时间列统一走 ``UTCDateTime`` —— 读出来必须带时区，写进去必须存 UTC。
+
+背景：库里存的是 naive UTC，读出来也是裸时间，于是每一处比较/输出都要自己记得
+补时区。项目里因此散了三份 ``_as_utc`` 和一堆 ``replace(tzinfo=UTC)``，还踩过一次
+
+    TypeError: can't compare offset-naive and offset-aware datetimes
+
+（P1a 的 CK 巡检排下一轮时间时炸的）。现在把边界收在 ``UTCDateTime``：
+写时 aware→UTC 裸值、naive 视为 UTC；读时一律补 UTC 时区。
+
+这组测试盯三件事：读出来是 aware、能和 ``datetime.now(UTC)`` 直接比、写进去
+落的是 UTC 而不是本地时间。
+"""
+
+from datetime import UTC, datetime, timedelta, timezone
+
+from sqlalchemy import create_engine, text
+from sqlalchemy.orm import sessionmaker
+
+from web.backend.database import Base, UTCDateTime
+from web.backend.models import AutomationRun, LoginTask
+
+
+class TestUtcDateTime:
+    def setup_method(self):
+        self.engine = create_engine("sqlite://")
+        Base.metadata.create_all(self.engine)
+        self.session = sessionmaker(bind=self.engine)()
+
+    def teardown_method(self):
+        self.session.close()
+
+    def _row(self, started_at):
+        self.session.add(
+            AutomationRun(job_key="k", started_at=started_at, status="success")
+        )
+        self.session.commit()
+        return self.session.query(AutomationRun).one()
+
+    def test_read_back_is_timezone_aware(self):
+        row = self._row(datetime(2026, 10, 2, 12, 0, tzinfo=UTC))
+        assert row.started_at.tzinfo is not None
+        assert row.started_at.utcoffset() == timedelta(0)
+
+    def test_read_back_value_can_compare_with_now(self):
+        """这条就是当初炸掉的写法：库里的时间直接和 datetime.now(UTC) 比。"""
+        row = self._row(datetime.now(UTC) - timedelta(minutes=1))
+        assert row.started_at < datetime.now(UTC)  # 不再 TypeError
+
+    def test_write_converts_local_aware_to_utc(self):
+        """带 +08:00 的时间要按 UTC 落库，不能把本地壁钟直接存进去。"""
+        local = datetime(2026, 10, 2, 20, 0, tzinfo=timezone(timedelta(hours=8)))
+        row = self._row(local)
+        assert row.started_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)
+        raw = self.session.execute(
+            text("SELECT started_at FROM automation_runs")
+        ).scalar()
+        assert str(raw).startswith("2026-10-02 12:00")
+
+    def test_naive_write_is_treated_as_utc(self):
+        """库里读出来的裸值再写回去（常见于搬迁/复制）不能被当成本地时间再减 8 小时。"""
+        naive_utc = datetime(2026, 10, 2, 12, 0)  # noqa: DTZ001 刻意构造裸 UTC
+        row = self._row(naive_utc)
+        assert row.started_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)
+
+    def test_none_stays_none(self):
+        assert UTCDateTime().process_bind_param(None, None) is None
+        assert UTCDateTime().process_result_value(None, None) is None
+
+    def test_all_model_datetime_columns_use_utc_type(self):
+        """新增时间列若忘了用 UTCDateTime，这里直接失败。"""
+        offenders = []
+        for table in Base.metadata.sorted_tables:
+            for column in table.columns:
+                if isinstance(column.type, UTCDateTime):
+                    continue
+                if str(column.type).upper().startswith("DATETIME"):
+                    offenders.append(f"{table.name}.{column.name}")
+        assert not offenders, f"这些时间列没用 UTCDateTime: {offenders}"
+
+    def test_login_task_attempt_at_round_trips_as_utc(self):
+        """真实模型抽查：写 aware、读 aware、能直接比较。"""
+        task = LoginTask(
+            batch_id="b",
+            account_id=1,
+            created_by=1,
+            attempt_at=datetime(2026, 10, 2, 12, 0, tzinfo=UTC),
+        )
+        self.session.add(task)
+        self.session.commit()
+        self.session.refresh(task)
+        assert task.attempt_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)
+        # 模型侧保证 aware，所以业务代码可以直接比较
+        assert task.attempt_at < datetime.now(UTC)

web/backend/database.py

@@ -1,11 +1,13 @@
 """数据库引擎与会话管理"""
 
 import os
+from datetime import UTC, datetime
 from pathlib import Path
 from urllib.parse import quote_plus
 
-from sqlalchemy import create_engine, event
+from sqlalchemy import DateTime, create_engine, event
 from sqlalchemy.orm import declarative_base, sessionmaker
+from sqlalchemy.types import TypeDecorator
 
 PROJECT_ROOT = Path(__file__).resolve().parents[2]
 
@@ -86,6 +88,41 @@ SessionLocal = sessionmaker(bind=engine, autocommit=False, autoflush=False)
 Base = declarative_base()
 
 
+class UTCDateTime(TypeDecorator):
+    """时间列统一走这里：**库里存 naive UTC，Python 侧永远是 tz-aware UTC**。
+
+    之前是全靠约定：写入用 ``datetime.now(UTC)``（MySQL 绑定参数会丢掉 tzinfo，
+    落库成 UTC 裸值），读出是裸值，谁要比较或输出就得自己记得补时区 —— 项目里
+    因此散了三份 ``_as_utc`` 和一堆 ``replace(tzinfo=UTC)``，还踩过一次
+    ``TypeError: can't compare offset-naive and offset-aware datetimes``。
+
+    这个装饰器把边界收在一处：
+
+    - 写：aware → 转 UTC 后去掉 tzinfo；naive → 视为已是 UTC，原样存；
+    - 读：一律补上 UTC 时区。
+
+    于是模型上的时间字段永远不会是裸时间，比较、相减、序列化都不必再各自处理。
+    底层 DDL 仍是 DATETIME（``impl`` 不变），**不需要迁移**。
+    """
+
+    impl = DateTime
+    cache_ok = True
+
+    def process_bind_param(self, value: datetime | None, dialect):
+        if value is None:
+            return None
+        if value.tzinfo is None:
+            return value
+        return value.astimezone(UTC).replace(tzinfo=None)
+
+    def process_result_value(self, value: datetime | None, dialect):
+        if value is None:
+            return None
+        if value.tzinfo is None:
+            return value.replace(tzinfo=UTC)
+        return value.astimezone(UTC)
+
+
 def get_db():
     """FastAPI 依赖：提供数据库会话，请求结束自动关闭。"""
     db = SessionLocal()

web/backend/models.py

@@ -7,7 +7,6 @@ from datetime import UTC, datetime
 from sqlalchemy import (
     JSON,
     Boolean,
-    DateTime,
     ForeignKey,
     Integer,
     String,
@@ -17,7 +16,7 @@ from sqlalchemy import (
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from .crypto_storage import EncryptedText
-from .database import Base
+from .database import Base, UTCDateTime
 from .huya_defaults import (
     HUYA_DEFAULT_BIND_ACT_ID,
     HUYA_DEFAULT_OUTER_ACT_ID,
@@ -50,12 +49,12 @@ class User(Base):
     custom_permissions: Mapped[list[str] | None] = mapped_column(
         JSON, nullable=True, comment="自定义权限列表，null表示使用角色默认权限"
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
     deleted_at: Mapped[datetime | None] = mapped_column(
-        DateTime, nullable=True, index=True
+        UTCDateTime, nullable=True, index=True
     )
     deleted_username: Mapped[str] = mapped_column(String(64), default="")
 
@@ -121,9 +120,9 @@ class Account(Base):
     xpd_balance: Mapped[int | None] = mapped_column(Integer, nullable=True)
     xpd_fragments: Mapped[int | None] = mapped_column(Integer, nullable=True)
     xpd_bind_status: Mapped[str] = mapped_column(String(32), default="")
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
     assigned_user: Mapped[User | None] = relationship(
@@ -153,8 +152,8 @@ class LoginTask(Base):
     cookie: Mapped[str] = mapped_column(EncryptedText(), default="")
     message: Mapped[str] = mapped_column(String(512), default="")
     created_by: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     # Cookie 有效性检测结果（持久化，刷新不丢失）
     ck_check_status: Mapped[str] = mapped_column(
         String(16), default=""
@@ -162,7 +161,7 @@ class LoginTask(Base):
     ck_check_result: Mapped[dict | None] = mapped_column(
         JSON, nullable=True
     )  # {fish_ball, nickname, level, message}
-    ck_checked_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    ck_checked_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     # 最近一次登录尝试的状态。批次只写 attempt_*，只有登录成功才会把新 CK
     # 写回 status/cookie/message，因此停止、失败、进程重启都不会破坏已有 CK。
     attempt_status: Mapped[str] = mapped_column(
@@ -174,12 +173,12 @@ class LoginTask(Base):
     attempt_batch_id: Mapped[str] = mapped_column(
         String(64), default="", server_default=""
     )
-    attempt_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    attempt_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     # 自动重登（P1b）用的退避状态。P1a 的巡检不碰这几个字段。
     relogin_attempts: Mapped[int] = mapped_column(
         Integer, default=0, server_default="0"
     )  # 连续重登尝试次数，成功即清零
-    relogin_next_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    relogin_next_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     relogin_last_error: Mapped[str] = mapped_column(
         String(512), default="", server_default=""
     )
@@ -208,8 +207,8 @@ class DouyuTask(Base):
     message: Mapped[str] = mapped_column(String(512), default="")
     result: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     created_by: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
 
     account: Mapped[Account] = relationship("Account", back_populates="douyu_tasks")
 
@@ -227,7 +226,7 @@ class DouyuWorkbenchAccount(Base):
     account_id: Mapped[int] = mapped_column(
         ForeignKey("accounts.id"), nullable=False, index=True
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
 
     __table_args__ = (
         UniqueConstraint(
@@ -247,7 +246,7 @@ class DouyuWorkbench(Base):
     )
     handbook_scope: Mapped[str] = mapped_column(String(16), nullable=False, index=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
     __table_args__ = (
@@ -288,15 +287,17 @@ class YybRechargeTask(Base):
     result: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     login_qr_data: Mapped[str] = mapped_column(EncryptedText(), default="")
     payment_qr_data: Mapped[str] = mapped_column(EncryptedText(), default="")
-    payment_started_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    payment_started_at: Mapped[datetime | None] = mapped_column(
+        UTCDateTime, nullable=True
+    )
     payment_qr_created_at: Mapped[datetime | None] = mapped_column(
-        DateTime, nullable=True
+        UTCDateTime, nullable=True
     )
     payment_last_checked_at: Mapped[datetime | None] = mapped_column(
-        DateTime, nullable=True
+        UTCDateTime, nullable=True
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
 
 
 class DouyuConfig(Base):
@@ -331,7 +332,7 @@ class DouyuConfig(Base):
     gift_id: Mapped[str] = mapped_column(String(64), default="23643")
     skin_id: Mapped[str] = mapped_column(String(64), default="2942")
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -347,7 +348,7 @@ class DouyuGoodsSnapshot(Base):
     status: Mapped[str] = mapped_column(String(32), default="")
     raw: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -365,7 +366,7 @@ class DouyuXpdGoodsSnapshot(Base):
     goods_left: Mapped[int | None] = mapped_column(Integer, nullable=True)
     raw: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -381,7 +382,7 @@ class DouyuEsportsGoodsSnapshot(Base):
     status: Mapped[str] = mapped_column(String(32), default="")
     raw: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -414,9 +415,9 @@ class HuyaAccount(Base):
     assigned_to: Mapped[int | None] = mapped_column(
         ForeignKey("users.id"), nullable=True, index=True
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
     assigned_user: Mapped[User | None] = relationship(
@@ -450,9 +451,9 @@ class HuyaRegisterBatch(Base):
     success_count: Mapped[int] = mapped_column(Integer, default=0)
     failed_count: Mapped[int] = mapped_column(Integer, default=0)
     stopped_count: Mapped[int] = mapped_column(Integer, default=0)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    started_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    started_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
 
     items: Mapped[list[HuyaRegisterItem]] = relationship(
         "HuyaRegisterItem", back_populates="batch", cascade="all, delete-orphan"
@@ -487,8 +488,8 @@ class HuyaRegisterItem(Base):
     password: Mapped[str] = mapped_column(EncryptedText(), default="")
     password_changed: Mapped[bool] = mapped_column(Boolean, default=False)
     cookie: Mapped[str] = mapped_column(EncryptedText(), default="")
-    started_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    started_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
 
     batch: Mapped[HuyaRegisterBatch] = relationship(
         "HuyaRegisterBatch", back_populates="items"
@@ -516,7 +517,9 @@ class HuyaRegisterSuccessLog(Base):
     created_by: Mapped[int | None] = mapped_column(
         ForeignKey("users.id"), nullable=True
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, index=True)
+    created_at: Mapped[datetime] = mapped_column(
+        UTCDateTime, default=_utcnow, index=True
+    )
 
 
 class HuyaTask(Base):
@@ -538,8 +541,8 @@ class HuyaTask(Base):
     message: Mapped[str] = mapped_column(String(512), default="")
     result: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     created_by: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
 
     account: Mapped[HuyaAccount] = relationship("HuyaAccount", back_populates="tasks")
 
@@ -557,7 +560,7 @@ class HuyaWorkbenchAccount(Base):
     account_id: Mapped[int] = mapped_column(
         ForeignKey("huya_accounts.id"), nullable=False, index=True
     )
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
 
     __table_args__ = (
         UniqueConstraint(
@@ -580,7 +583,7 @@ class HuyaWorkbench(Base):
     )
     handbook_scope: Mapped[str] = mapped_column(String(16), nullable=False, index=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
     __table_args__ = (
@@ -606,7 +609,7 @@ class HuyaConfig(Base):
         String(16), default=HUYA_DEFAULT_PAY_CHANNEL
     )
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -624,7 +627,7 @@ class HuyaGoodsSnapshot(Base):
     remain_text: Mapped[str] = mapped_column(String(64), default="")
     raw: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -648,7 +651,7 @@ class HuyaRechargeGoodsSnapshot(Base):
     task_name: Mapped[str] = mapped_column(String(256), default="")
     raw: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -684,7 +687,7 @@ class AuditLog(Base):
     detail: Mapped[str] = mapped_column(Text, default="")
     # 旧记录未标记结果时为 NULL，避免把历史操作误判成失败。
     success: Mapped[bool | None] = mapped_column(Boolean, nullable=True, index=True)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
+    created_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
 
 
 class AutomationJob(Base):
@@ -702,14 +705,14 @@ class AutomationJob(Base):
     batch_size: Mapped[int] = mapped_column(Integer, default=200, server_default="200")
     concurrency: Mapped[int] = mapped_column(Integer, default=5, server_default="5")
     config: Mapped[dict | None] = mapped_column(JSON, nullable=True)
-    last_run_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
-    next_run_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    last_run_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
+    next_run_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     last_status: Mapped[str] = mapped_column(String(16), default="", server_default="")
     last_message: Mapped[str] = mapped_column(
         String(512), default="", server_default=""
     )
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow
+        UTCDateTime, default=_utcnow, onupdate=_utcnow
     )
 
 
@@ -720,8 +723,8 @@ class AutomationRun(Base):
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
     job_key: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
-    started_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow)
-    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    started_at: Mapped[datetime] = mapped_column(UTCDateTime, default=_utcnow)
+    finished_at: Mapped[datetime | None] = mapped_column(UTCDateTime, nullable=True)
     status: Mapped[str] = mapped_column(
         String(16), default="running", server_default="running"
     )  # running / success / failed / skipped