feat(metrics): Add status code tracking and improve path metrics handling

- Implement status code statistics tracking in Collector
- Update PathMetrics type to use pointer-based access
- Enhance atomic operations for request and error count tracking
- Modify type assertions to use pointer-based type conversion

internal/metrics/collector.go

@@ -127,10 +127,19 @@ func (c *Collector) RecordRequest(path string, status int, latency time.Duration
 		}
 	}
 
+	// 更新状态码统计
+	statusKey := fmt.Sprintf("%d", status)
+	if counter, ok := c.statusCodeStats.Load(statusKey); ok {
+		atomic.AddInt64(counter.(*int64), 1)
+	} else {
+		var count int64 = 1
+		c.statusCodeStats.Store(statusKey, &count)
+	}
+
 	// 更新路径统计
 	c.pathStatsMutex.Lock()
 	if value, ok := c.pathStats.Load(path); ok {
-		stat := value.(models.PathMetrics)
+		stat := value.(*models.PathMetrics)
 		atomic.AddInt64(&stat.RequestCount, 1)
 		if status >= 400 {
 			atomic.AddInt64(&stat.ErrorCount, 1)
@@ -303,7 +312,7 @@ func (c *Collector) validateLoadedData() error {
 	// 验证路径统计
 	var totalPathRequests int64
 	c.pathStats.Range(func(_, value interface{}) bool {
-		stats := value.(models.PathMetrics)
+		stats := value.(*models.PathMetrics)
 		if stats.RequestCount < 0 || stats.ErrorCount < 0 {
 			return false
 		}

internal/models/metrics.go

@@ -11,6 +11,16 @@ type PathStats struct {
 	LatencySum atomic.Int64
 }
 
+// PathMetrics 路径指标
+type PathMetrics struct {
+	Path             string `json:"path"`
+	RequestCount     int64  `json:"request_count"`
+	ErrorCount       int64  `json:"error_count"`
+	TotalLatency     int64  `json:"total_latency"`
+	BytesTransferred int64  `json:"bytes_transferred"`
+	AvgLatency       string `json:"avg_latency"`
+}
+
 type HistoricalMetrics struct {
 	Timestamp     string  `json:"timestamp"`
 	TotalRequests int64   `json:"total_requests"`

internal/models/request.go

@@ -15,16 +15,6 @@ type RequestLog struct {
 	ClientIP  string    `json:"ClientIP"`
 }
 
-// PathMetrics 路径指标
-type PathMetrics struct {
-	Path             string `json:"path"`
-	RequestCount     int64  `json:"request_count"`
-	ErrorCount       int64  `json:"error_count"`
-	TotalLatency     int64  `json:"-"`
-	AvgLatency       string `json:"avg_latency"`
-	BytesTransferred int64  `json:"bytes_transferred"`
-}
-
 // RequestQueue 请求队列
 type RequestQueue struct {
 	sync.RWMutex