feat: 完成模拟交易闭环、App 与 A 股行情接入

统一单入口 Go 工程与前端依赖目录，增加后台供应商配置、候选审核、计划预算、成交冲正、持仓复盘和站内通知。接入策略版本、Python 回测、可配置 A 股公开行情及 zap 文件轮转日志，补充迁移、契约与验证。

internal/service/admin_credential.go

@@ -0,0 +1,42 @@
+package service
+
+import (
+	"context"
+	"strings"
+	"time"
+
+	"git.sundynix.cn/Blizzard/Veyra/internal/apperror"
+	"golang.org/x/crypto/bcrypt"
+)
+
+type AdminCredentialRepository interface {
+	ChangeAdminCredential(context.Context, string, string, string, time.Time) (string, error)
+}
+type AdminCredentialService struct {
+	repo        AdminCredentialRepository
+	development bool
+}
+
+func NewAdminCredentialService(repo AdminCredentialRepository, development bool) *AdminCredentialService {
+	return &AdminCredentialService{repo: repo, development: development}
+}
+
+// Set changes only an existing active administrator and revokes its old sessions.
+func (s *AdminCredentialService) Set(ctx context.Context, previousLogin, login, password string) (string, error) {
+	if !s.development {
+		return "", apperror.ErrForbidden
+	}
+	if s.repo == nil {
+		return "", apperror.ErrUnavailable
+	}
+	previousLogin = strings.ToLower(strings.TrimSpace(previousLogin))
+	login = strings.ToLower(strings.TrimSpace(login))
+	if !loginPattern.MatchString(previousLogin) || !loginPattern.MatchString(login) || len(password) < 8 || len(password) > 72 {
+		return "", apperror.ErrInvalidInput
+	}
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return "", apperror.ErrUnavailable
+	}
+	return s.repo.ChangeAdminCredential(ctx, previousLogin, login, string(hash), time.Now().UTC())
+}