重构消息队列连接管理，支持多数据源配置

主要变更：
1. 重构NATS、RabbitMQ和Redis连接管理模块，支持多数据源配置
2. 统一连接管理接口，增加数据源名称参数
3. 优化连接状态检查和错误处理
4. 增加连接池管理和资源清理机制
5. 改进日志输出格式和内容

message/store.go

@@ -0,0 +1,125 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package message
+
+import "fmt"
+
+type RetentionPolicy int
+
+const (
+	// LimitsPolicy (default) means that messages are retained until any given limit is reached.
+	// This could be one of MaxMsgs, MaxBytes, or MaxAge.
+	LimitsPolicy RetentionPolicy = iota
+	// InterestPolicy specifies that when all known consumers have acknowledged a message it can be removed.
+	InterestPolicy
+	// WorkQueuePolicy specifies that when the first worker or subscriber acknowledges the message it can be removed.
+	WorkQueuePolicy
+)
+
+// MarshalJSON 将 RetentionPolicy 序列化为字符串
+func (rp RetentionPolicy) MarshalJSON() ([]byte, error) {
+	switch rp {
+	case LimitsPolicy:
+		return []byte(`"limits"`), nil
+	case InterestPolicy:
+		return []byte(`"interest"`), nil
+	case WorkQueuePolicy:
+		return []byte(`"workqueue"`), nil
+	default:
+		return nil, fmt.Errorf("can not marshal %v", rp)
+	}
+}
+
+// UnmarshalJSON 将字符串反序列化为 RetentionPolicy
+func (rp *RetentionPolicy) UnmarshalJSON(data []byte) error {
+	switch string(data) {
+	case `"limits"`:
+		*rp = LimitsPolicy
+	case `"interest"`:
+		*rp = InterestPolicy
+	case `"workqueue"`:
+		*rp = WorkQueuePolicy
+	default:
+		return fmt.Errorf("unknown retention policy: %s", string(data))
+	}
+	return nil
+}
+
+type DiscardPolicy int
+
+const (
+	// DiscardOld will remove older messages to return to the limits.
+	DiscardOld = iota
+	// DiscardNew will error on a StoreMsg call
+	DiscardNew
+)
+
+// MarshalJSON 将 DiscardPolicy 序列化为字符串
+func (dp DiscardPolicy) MarshalJSON() ([]byte, error) {
+	switch dp {
+	case DiscardOld:
+		return []byte(`"old"`), nil
+	case DiscardNew:
+		return []byte(`"new"`), nil
+	default:
+		return nil, fmt.Errorf("can not marshal %v", dp)
+	}
+}
+
+// UnmarshalJSON 将字符串反序列化为 DiscardPolicy
+func (dp *DiscardPolicy) UnmarshalJSON(data []byte) error {
+	switch string(data) {
+	case `"old"`:
+		*dp = DiscardOld
+	case `"new"`:
+		*dp = DiscardNew
+	default:
+		return fmt.Errorf("unknown discard policy: %s", string(data))
+	}
+	return nil
+}
+
+type StorageType int
+
+const (
+	// FileStorage specifies on disk, designated by the JetStream config StoreDir.
+	FileStorage = StorageType(22)
+	// MemoryStorage specifies in memory only.
+	MemoryStorage = StorageType(33)
+)
+
+// MarshalJSON 将 StorageType 序列化为字符串
+func (st StorageType) MarshalJSON() ([]byte, error) {
+	switch st {
+	case MemoryStorage:
+		return []byte(`"memory"`), nil
+	case FileStorage:
+		return []byte(`"file"`), nil
+	default:
+		return nil, fmt.Errorf("can not marshal %v", st)
+	}
+}
+
+// UnmarshalJSON 将字符串反序列化为 StorageType
+func (st *StorageType) UnmarshalJSON(data []byte) error {
+	switch string(data) {
+	case `"memory"`:
+		*st = MemoryStorage
+	case `"file"`:
+		*st = FileStorage
+	default:
+		return fmt.Errorf("unknown storage type: %s", string(data))
+	}
+	return nil
+}