feat: 实现基于 Redis 的延迟任务队列和工作器，支持周期性交易处理等后台任务调度。

cmd/server/main.go

@@ -5,10 +5,12 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"time"
 
 	"accounting-app/internal/cache"
 	"accounting-app/internal/config"
 	"accounting-app/internal/database"
+	"accounting-app/internal/mq"
 	"accounting-app/internal/repository"
 	"accounting-app/internal/router"
 	"accounting-app/internal/service"
@@ -97,6 +99,7 @@ func main() {
 	if err != nil {
 		// Redis not available - fall back to old system
 		log.Printf("Warning: Redis connection failed (%v), falling back to non-cached exchange rate system", err)
+		log.Printf("Warning: Recurring transaction MQ system disabled (requires Redis)")
 
 		// Use old scheduler
 		scheduler := service.NewExchangeRateScheduler(yunAPIClient, cfg.SyncInterval)
@@ -116,6 +119,22 @@ func main() {
 		// Start the new SyncScheduler in background
 		// This will perform initial sync immediately (Requirement 3.1)
 		go syncScheduler.Start(ctx)
+
+		// Initialize and start MQ task system for recurring transactions
+		recurringTaskSystem, err := mq.InitRecurringTaskSystem(
+			ctx,
+			redisClient.Client(),
+			db,
+			5*time.Second, // Poll interval: 检查延迟任务的间隔
+			2,             // Worker count: 并发处理任务的数量
+		)
+		if err != nil {
+			log.Printf("Warning: Failed to initialize recurring task system: %v", err)
+		} else {
+			// Start MQ worker in background
+			go recurringTaskSystem.Start(ctx)
+			log.Println("Recurring transaction MQ system started")
+		}
 	}
 
 	// Get port from config or environment