feat: 新增周期性交易处理器及任务队列，实现周期性交易的自动化处理、并发安全与幂等性调度。

internal/mq/task_queue.go

@@ -18,6 +18,13 @@ const (
 	TaskTypeRecurringTransaction TaskType = "recurring_transaction"
 	// TaskTypeAllocationRule 分配规则执行任务
 	TaskTypeAllocationRule TaskType = "allocation_rule"
+
+	// Redis Key Prefixes
+	KeyPrefixDefault    = "novault:tasks"
+	KeySuffixDelayed    = ":delayed"
+	KeySuffixReady      = ":ready"
+	KeySuffixProcessing = ":processing"
+	KeyPrefixLock       = "novault:lock:"
 )
 
 // DelayedTask 延迟任务结构
@@ -50,17 +57,22 @@ type TaskQueue struct {
 // NewTaskQueue 创建任务队列实例
 func NewTaskQueue(client *redis.Client, keyPrefix string) *TaskQueue {
 	if keyPrefix == "" {
-		keyPrefix = "novault:tasks"
+		keyPrefix = KeyPrefixDefault
 	}
 	return &TaskQueue{
 		client:        client,
 		keyPrefix:     keyPrefix,
-		delayedKey:    keyPrefix + ":delayed",
-		readyKey:      keyPrefix + ":ready",
-		processingKey: keyPrefix + ":processing",
+		delayedKey:    keyPrefix + KeySuffixDelayed,
+		readyKey:      keyPrefix + KeySuffixReady,
+		processingKey: keyPrefix + KeySuffixProcessing,
 	}
 }
 
+// GenerateLockKey 生成分布式锁 Key
+func GenerateLockKey(taskID string) string {
+	return KeyPrefixLock + "recurring:" + taskID
+}
+
 // Schedule 调度延迟任务
 func (q *TaskQueue) Schedule(ctx context.Context, task *DelayedTask) error {
 	// 序列化任务