enhance(cache):为缓存增加60秒内的随机秒数，以避免缓存雪崩。

cache/abstract.go

@@ -3,6 +3,7 @@ package cache
 import (
 	"electricity_bill_calc/global"
 	"fmt"
+	"math/rand"
 	"strings"
 	"time"
 
@@ -23,9 +24,10 @@ const (
 func Cache[T interface{}](key string, value *T, expires time.Duration) error {
 	var err error
 	if expires > 0 {
+		realExpires := expires + time.Duration(rand.Int63n(60))*time.Second
 		setCmd := global.RedisConn.B().Set().
 			Key(key).Value(rueidis.JSON(value)).
-			ExSeconds(int64(expires.Seconds())).
+			ExSeconds(int64(realExpires.Seconds())).
 			Build()
 		err = global.RedisConn.Do(global.Ctx, setCmd).Error()
 	} else {