feat: 从黄果 NET hgdjnet-server 9bfbafe 导入 HKDJ 官网后端

来源：hgdjnet-server 9bfbafe10d417deea959bd53117bc88a10e60a83
项目身份 HKDJ / JHA-216，独立官网仓库，Jenkins 守卫键 hkdjnet
测试目录 /server/hkdj_net，App/Web API 30331/30332

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

pub/common/random/number.go

@@ -0,0 +1,53 @@
+package random
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+const letterBytesAll = "0123456789abcdefghijklmnopqrstvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+func init() {
+	rand.Seed(time.Now().Unix())
+}
+
+func Int(n int) int {
+	return rand.Intn(n)
+}
+
+func SliceRand(ids []int64) (result []int64) {
+	result = make([]int64, 0)
+	if len(ids) <= 0 {
+		return
+	}
+	copy := make([]int64, 0)
+	for _, id := range ids {
+		copy = append(copy, id)
+	}
+	num := Int(len(copy)) + 1
+	for i := 0; i < num; i++ {
+		index := Int(len(copy))
+		result = append(result, copy[index])
+		copy = append(copy[:index], copy[index+1:]...)
+	}
+	return
+}
+
+func RandDigits(n uint) string {
+	s := ""
+	for n != 0 {
+		s += fmt.Sprintf("%d", rand.Intn(10))
+		n--
+	}
+	return s
+}
+
+// RandStrRandrAll 生成指定位数的随机数
+func RandStrRandrAll(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = letterBytesAll[rand.Int63()%int64(len(letterBytesAll))]
+	}
+	return string(b)
+}