Unify all timestamps to Beijing time (UTC+8)

- Add BEIJING_TZ constant in config.py
- Replace all timezone.utc references across 11 files
- Device-reported times, DB defaults, protocol sync all use Beijing time

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

app/models.py

@@ -1,4 +1,6 @@
-from datetime import datetime, timezone
+from datetime import datetime
+
+from app.config import BEIJING_TZ
 
 from sqlalchemy import (
     BigInteger,
@@ -17,8 +19,8 @@ from sqlalchemy.orm import Mapped, mapped_column, relationship
 from app.database import Base
 
 
-def _utcnow() -> datetime:
-    return datetime.now(timezone.utc)
+def _now_beijing() -> datetime:
+    return datetime.now(BEIJING_TZ)
 
 
 class Device(Base):
@@ -39,9 +41,9 @@ class Device(Base):
     imsi: Mapped[str | None] = mapped_column(String(20), nullable=True)
     timezone: Mapped[str] = mapped_column(String(30), default="+8", nullable=False)
     language: Mapped[str] = mapped_column(String(10), default="cn", nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
     updated_at: Mapped[datetime | None] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow, nullable=True
+        DateTime, default=_now_beijing, onupdate=_now_beijing, nullable=True
     )
 
     # Relationships
@@ -102,7 +104,7 @@ class LocationRecord(Base):
     address: Mapped[str | None] = mapped_column(Text, nullable=True)
     raw_data: Mapped[str | None] = mapped_column(Text, nullable=True)
     recorded_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="locations")
 
@@ -147,7 +149,7 @@ class AlarmRecord(Base):
     address: Mapped[str | None] = mapped_column(Text, nullable=True)
     acknowledged: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
     recorded_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="alarms")
 
@@ -175,7 +177,7 @@ class HeartbeatRecord(Base):
     battery_level: Mapped[int] = mapped_column(Integer, nullable=False)
     gsm_signal: Mapped[int] = mapped_column(Integer, nullable=False)
     extension_data: Mapped[dict | None] = mapped_column(JSON, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="heartbeats")
 
@@ -215,7 +217,7 @@ class AttendanceRecord(Base):
     lbs_data: Mapped[dict | None] = mapped_column(JSON, nullable=True)
     address: Mapped[str | None] = mapped_column(Text, nullable=True)
     recorded_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="attendance_records")
 
@@ -254,7 +256,7 @@ class BluetoothRecord(Base):
     latitude: Mapped[float | None] = mapped_column(Float, nullable=True)
     longitude: Mapped[float | None] = mapped_column(Float, nullable=True)
     recorded_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="bluetooth_records")
 
@@ -282,9 +284,9 @@ class BeaconConfig(Base):
     longitude: Mapped[float | None] = mapped_column(Float, nullable=True)
     address: Mapped[str | None] = mapped_column(Text, nullable=True)
     status: Mapped[str] = mapped_column(String(20), default="active", nullable=False)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
     updated_at: Mapped[datetime | None] = mapped_column(
-        DateTime, default=_utcnow, onupdate=_utcnow, nullable=True
+        DateTime, default=_now_beijing, onupdate=_now_beijing, nullable=True
     )
 
     def __repr__(self) -> str:
@@ -312,7 +314,7 @@ class CommandLog(Base):
     )  # pending, sent, success, failed
     sent_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
     response_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     device: Mapped["Device"] = relationship(back_populates="command_logs")
 
@@ -336,7 +338,7 @@ class ApiKey(Base):
     )  # read, write, admin
     is_active: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
     last_used_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(DateTime, default=_utcnow, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=_now_beijing, nullable=False)
 
     def __repr__(self) -> str:
         return f"<ApiKey(id={self.id}, name={self.name}, permissions={self.permissions})>"