feat(db): add pgxpool with health check and integration test

internal/infra/db/postgres_test.go

@@ -0,0 +1,41 @@
+//go:build integration
+
+package db_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	tcpg "github.com/testcontainers/testcontainers-go/modules/postgres"
+
+	mydb "github.com/yan1h/agent-coding-workflow/internal/infra/db"
+)
+
+// TestNewPool_ConnectsAndPings 用 testcontainers 起一个真实的 Postgres，
+// 验证 NewPool 能连上、HealthCheck 能 Ping 通。
+// 仅在 integration build tag 下编译/运行；本地 `go test ./...` 会跳过。
+func TestNewPool_ConnectsAndPings(t *testing.T) {
+	ctx := context.Background()
+
+	// v0.42.0 起 RunContainer 已 Deprecated，统一用 Run(ctx, image, opts...)。
+	container, err := tcpg.Run(ctx, "postgres:16-alpine",
+		tcpg.WithDatabase("acw"),
+		tcpg.WithUsername("acw"),
+		tcpg.WithPassword("acw"),
+	)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = container.Terminate(ctx) })
+
+	dsn, err := container.ConnectionString(ctx, "sslmode=disable")
+	require.NoError(t, err)
+
+	pool, err := mydb.NewPool(ctx, dsn)
+	require.NoError(t, err)
+	t.Cleanup(pool.Close)
+
+	hctx, cancel := context.WithTimeout(ctx, 2*time.Second)
+	defer cancel()
+	require.NoError(t, mydb.HealthCheck(hctx, pool))
+}