修复统计数据时区问题: 使用本地时区(Asia/Shanghai)计算今日和本周统计

问题: 原代码使用SQLite的DATE('now')获取的是UTC时间，不是本地时间
解决: 在Python中使用pytz计算本地时区的今日/本周时间范围，转换为UTC后查询数据库

database.py

@@ -312,25 +312,44 @@ class Database:
 
     def get_statistics(self) -> Dict[str, Any]:
         """获取统计信息"""
+        import pytz
+
         conn = self.get_connection()
         cursor = conn.cursor()
 
-        # 总短信数
+        # 获取总短信数
         cursor.execute('SELECT COUNT(*) as total FROM sms_messages')
         total = cursor.fetchone()['total']
 
+        # 使用本地时区计算今日和本周的 UTC 时间范围
+        local_tz = pytz.timezone(self.timezone)
+        local_now = datetime.now(local_tz)
+
+        # 今日本地时间的开始和结束
+        today_start_local = local_now.replace(hour=0, minute=0, second=0, microsecond=0)
+        today_end_local = today_start_local + timedelta(days=1)
+
+        # 转换为 UTC 时间
+        today_start_utc = today_start_local.astimezone(pytz.UTC)
+        today_end_utc = today_end_local.astimezone(pytz.UTC)
+
         # 今日短信数
         cursor.execute('''
             SELECT COUNT(*) as today FROM sms_messages
-            WHERE DATE(created_at) = DATE('now')
-        ''')
+            WHERE created_at >= ? AND created_at < ?
+        ''', (today_start_utc.strftime('%Y-%m-%d %H:%M:%S'), today_end_utc.strftime('%Y-%m-%d %H:%M:%S')))
         today = cursor.fetchone()['today']
 
+        # 本周开始时间（本周一 00:00:00 本地时间）
+        weekday = local_now.weekday()
+        week_start_local = (local_now - timedelta(days=weekday)).replace(hour=0, minute=0, second=0, microsecond=0)
+        week_start_utc = week_start_local.astimezone(pytz.UTC)
+
         # 本周短信数
         cursor.execute('''
             SELECT COUNT(*) as week FROM sms_messages
-            WHERE created_at >= datetime('now', '-7 days')
-        ''')
+            WHERE created_at >= ?
+        ''', (week_start_utc.strftime('%Y-%m-%d %H:%M:%S'),))
         week = cursor.fetchone()['week']
 
         # 签名验证占比