fix: admin 审批链路查询条件缺失与网关路由缺失

SearchUserVerifications 查询条件硬编码了 user_id=0 导致 admin 查询
始终返回空列表，改为条件构建模式。envoy 缺少 /api/v1/admin 前缀
路由导致审批接口 404。新增 users-rpc 启动时从环境变量自动初始化
管理员账户。

app/users/rpc/admin_init.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"os"
+	"strings"
+
+	"juwan-backend/app/snowflake/rpc/snowflake"
+	"juwan-backend/app/users/rpc/internal/models/users"
+	"juwan-backend/app/users/rpc/internal/svc"
+	"juwan-backend/common/utils/pwdUtils"
+
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+func initAdmin(svcCtx *svc.ServiceContext) {
+	username := strings.TrimSpace(os.Getenv("ADMIN_USERNAME"))
+	password := strings.TrimSpace(os.Getenv("ADMIN_PASSWORD"))
+	email := strings.TrimSpace(os.Getenv("ADMIN_EMAIL"))
+	if username == "" || password == "" || email == "" {
+		return
+	}
+
+	ctx := context.Background()
+	exists, _ := svcCtx.UsersModelRW.Users.Query().Where(users.UsernameEQ(username)).Exist(ctx)
+	if exists {
+		return
+	}
+
+	hashedPassword, err := pwdUtils.HashPassword(password)
+	if err != nil {
+		logx.Errorf("hash admin password: %v", err)
+		return
+	}
+
+	resp, err := svcCtx.Snowflake.NextId(ctx, &snowflake.NextIdReq{})
+	if err != nil {
+		logx.Errorf("generate admin user ID: %v", err)
+		return
+	}
+
+	_, err = svcCtx.UsersModelRW.Users.Create().
+		SetID(resp.Id).
+		SetUsername(username).
+		SetPasswordHash(hashedPassword).
+		SetEmail(email).
+		SetPhone("").
+		SetBio("").
+		SetAvatar("").
+		SetCurrentRole("consumer").
+		SetNickname(username).
+		SetIsAdmin(true).
+		Save(ctx)
+	if err != nil {
+		logx.Errorf("create admin user: %v", err)
+		return
+	}
+
+	logx.Infof("initialized admin user: %s", username)
+}