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。

internal/handler/task_queue_handler.go

@@ -0,0 +1,78 @@
+package handler
+
+import (
+	"net/http"
+
+	"accounting-app/internal/mq"
+
+	"github.com/gin-gonic/gin"
+)
+
+// TaskQueueHandler 任务队列状态查询 Handler
+type TaskQueueHandler struct {
+	taskSystem *mq.RecurringTaskSystem
+}
+
+// NewTaskQueueHandler 创建任务队列 Handler
+func NewTaskQueueHandler(taskSystem *mq.RecurringTaskSystem) *TaskQueueHandler {
+	return &TaskQueueHandler{
+		taskSystem: taskSystem,
+	}
+}
+
+// GetStats 获取任务队列统计信息
+// GET /api/v1/admin/tasks/stats
+func (h *TaskQueueHandler) GetStats(c *gin.Context) {
+	if h.taskSystem == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"success": false,
+			"error":   "Task system not available (Redis required)",
+		})
+		return
+	}
+
+	stats := h.taskSystem.GetStats(c.Request.Context())
+
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"data":    stats,
+	})
+}
+
+// GetPendingTasks 获取即将执行的任务列表
+// GET /api/v1/admin/tasks/pending
+func (h *TaskQueueHandler) GetPendingTasks(c *gin.Context) {
+	if h.taskSystem == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"success": false,
+			"error":   "Task system not available (Redis required)",
+		})
+		return
+	}
+
+	tasks, err := h.taskSystem.Queue.GetPendingTasks(c.Request.Context(), 50)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"success": false,
+			"error":   err.Error(),
+		})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"data": gin.H{
+			"count": len(tasks),
+			"tasks": tasks,
+		},
+	})
+}
+
+// RegisterRoutes 注册路由
+func (h *TaskQueueHandler) RegisterRoutes(rg *gin.RouterGroup) {
+	tasks := rg.Group("/admin/tasks")
+	{
+		tasks.GET("/stats", h.GetStats)
+		tasks.GET("/pending", h.GetPendingTasks)
+	}
+}