chore: baseline snapshot before moderation-strictness feature

Repo .git was damaged (refs/ missing, index truncated, object store near-empty).
Repaired via git init (rebuilt refs), stale index preserved as .git/index.corrupt-20260910.bak,
then full worktree committed as a rollback baseline.

internal/db/main_test.go

@@ -0,0 +1,18 @@
+// Copyright 2023 E99p1ant. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package db
+
+import (
+	"testing"
+
+	"gorm.io/gorm"
+
+	"github.com/tamakyi/TamaBox/internal/dbutil"
+)
+
+// newTestDB returns a test database instance with the cleanup function.
+func newTestDB(t *testing.T) (*gorm.DB, func(...string) error) {
+	return dbutil.NewTestDB(t, AllTables...)
+}