feat: 增强桌面启动失败提示与测试覆盖

backend/internal/database/database.go

@@ -2,6 +2,7 @@ package database
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -17,6 +18,8 @@ import (
 	pkglogger "nex/backend/pkg/logger"
 )
 
+var ErrMigration = errors.New("数据库迁移失败")
+
 func Init(cfg *config.DatabaseConfig, zapLogger *zap.Logger) (*gorm.DB, error) {
 	moduleLogger := pkglogger.WithModule(zapLogger, "database")
 
@@ -26,7 +29,7 @@ func Init(cfg *config.DatabaseConfig, zapLogger *zap.Logger) (*gorm.DB, error) {
 	}
 
 	if err := runMigrations(db, cfg.Driver, moduleLogger); err != nil {
-		return nil, fmt.Errorf("数据库迁移失败: %w", err)
+		return nil, fmt.Errorf("%w: %w", ErrMigration, err)
 	}
 
 	configurePool(db, cfg, moduleLogger)