refactor: 移除 infrastructure 目录 (#108)

* refactor: 迁移初始化 db 和 redis 到 repository

* refactor: 迁移 errors 到 pkg

backend/internal/repository/integration_harness_test.go

@@ -17,7 +17,6 @@ import (
 
 	dbent "github.com/Wei-Shaw/sub2api/ent"
 	_ "github.com/Wei-Shaw/sub2api/ent/runtime"
-	"github.com/Wei-Shaw/sub2api/internal/infrastructure"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/timezone"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
@@ -97,7 +96,7 @@ func TestMain(m *testing.M) {
 		log.Printf("failed to open sql db: %v", err)
 		os.Exit(1)
 	}
-	if err := infrastructure.ApplyMigrations(ctx, integrationDB); err != nil {
+	if err := ApplyMigrations(ctx, integrationDB); err != nil {
 		log.Printf("failed to apply db migrations: %v", err)
 		os.Exit(1)
 	}