fix(软删除): 修复删除钩子调用链并跳过无Docker测试

软删除钩子改用 next.Mutate 处理更新，避免 mutation 类型不匹配
集成测试检测 Docker 可用性，无 Docker 自动跳过

backend/ent/schema/mixins/soft_delete.go

@@ -112,9 +112,6 @@ func (d SoftDeleteMixin) Hooks() []ent.Hook {
 					SetOp(ent.Op)
 					SetDeletedAt(time.Time)
 					WhereP(...func(*sql.Selector))
-					Client() interface {
-						Mutate(context.Context, ent.Mutation) (ent.Value, error)
-					}
 				})
 				if !ok {
 					return nil, fmt.Errorf("unexpected mutation type %T", m)
@@ -125,7 +122,7 @@ func (d SoftDeleteMixin) Hooks() []ent.Hook {
 				mx.SetOp(ent.OpUpdate)
 				// 设置删除时间为当前时间
 				mx.SetDeletedAt(time.Now())
-				return mx.Client().Mutate(ctx, m)
+				return next.Mutate(ctx, m)
 			})
 		},
 	}

backend/internal/middleware/rate_limiter_integration_test.go

@@ -7,6 +7,9 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strconv"
 	"testing"
 	"time"
 
@@ -88,6 +91,7 @@ func performRequest(router *gin.Engine) *httptest.ResponseRecorder {
 
 func startRedis(t *testing.T, ctx context.Context) *redis.Client {
 	t.Helper()
+	ensureDockerAvailable(t)
 
 	redisContainer, err := tcredis.Run(ctx, redisImageTag)
 	require.NoError(t, err)
@@ -112,3 +116,43 @@ func startRedis(t *testing.T, ctx context.Context) *redis.Client {
 
 	return rdb
 }
+
+func ensureDockerAvailable(t *testing.T) {
+	t.Helper()
+	if dockerAvailable() {
+		return
+	}
+	t.Skip("Docker 未启用，跳过依赖 testcontainers 的集成测试")
+}
+
+func dockerAvailable() bool {
+	if os.Getenv("DOCKER_HOST") != "" {
+		return true
+	}
+
+	socketCandidates := []string{
+		"/var/run/docker.sock",
+		filepath.Join(os.Getenv("XDG_RUNTIME_DIR"), "docker.sock"),
+		filepath.Join(userHomeDir(), ".docker", "run", "docker.sock"),
+		filepath.Join(userHomeDir(), ".docker", "desktop", "docker.sock"),
+		filepath.Join("/run/user", strconv.Itoa(os.Getuid()), "docker.sock"),
+	}
+
+	for _, socket := range socketCandidates {
+		if socket == "" {
+			continue
+		}
+		if _, err := os.Stat(socket); err == nil {
+			return true
+		}
+	}
+	return false
+}
+
+func userHomeDir() string {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	return home
+}