fix: 修复6个边缘侧问题 + 单元测试

1. 删除 ConfigAgent (与 MQTT 配置更新重叠且未启用)
2. OTA 完整安装流程: 解压tar.gz -> 校验ELF -> 替换二进制 -> systemctl重启
3. StreamManager stopAll 添加 Wait() 防止僵尸进程
4. InferClient socket 读写添加 timeout 防止永久阻塞
5. Heartbeat 集成 NPU 监控 (npu-smi + fallback 脚本)
6. 配置更新时动态重启 ffmpeg 以应用新 fps

internal/infer/client.go

@@ -208,10 +208,17 @@ func (c *Client) send(conn net.Conn, f stream.Frame) error {
 	if err != nil {
 		return err
 	}
+	conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
+	defer conn.SetWriteDeadline(time.Time{})
 	return writeMsg(conn, data)
 }
 
 func (c *Client) recv(conn net.Conn) (*resultMsg, error) {
+	// Set read deadline to prevent blocking forever if inference server hangs
+	// 30s timeout covers even slow NPU inference on large images
+	conn.SetReadDeadline(time.Now().Add(30 * time.Second))
+	defer conn.SetReadDeadline(time.Time{}) // reset after read
+
 	data, err := readMsg(conn)
 	if err != nil {
 		return nil, err

internal/infer/client_test.go

@@ -0,0 +1,80 @@
+package infer
+
+import (
+	"testing"
+
+	"tianyan-edge/internal/config"
+)
+
+func TestIsDuplicate(t *testing.T) {
+	cfg := &config.Config{DedupWindowSec: 30}
+	c := &Client{
+		cfg:   cfg,
+		dedup: &dedupState{seen: make(map[string]float64)},
+	}
+
+	// First detection should NOT be duplicate (uses default config dedup window of 30s)
+	// ts=100.0, key="cam-001|person" — first time, not duplicate
+	if c.isDuplicate("cam-001", "person", 100.0) {
+		t.Error("first detection should not be duplicate")
+	}
+
+	// Same device+class within window should BE duplicate
+	// ts=105.0, 105-100=5 < 30, duplicate
+	if !c.isDuplicate("cam-001", "person", 105.0) {
+		t.Error("same event within window should be duplicate")
+	}
+
+	// Same device+class outside window should NOT be duplicate
+	// ts=200.0, 200-105=95 > 30, not duplicate (updates the timestamp)
+	if c.isDuplicate("cam-001", "person", 200.0) {
+		t.Error("same event outside window should not be duplicate")
+	}
+
+	// Different class should NOT be duplicate
+	if c.isDuplicate("cam-001", "car", 105.0) {
+		t.Error("different class should not be duplicate")
+	}
+
+	// Different device should NOT be duplicate
+	if c.isDuplicate("cam-002", "person", 105.0) {
+		t.Error("different device should not be duplicate")
+	}
+}
+
+func TestDedupMapCleanup(t *testing.T) {
+	cfg := &config.Config{DedupWindowSec: 30}
+	c := &Client{
+		cfg:   cfg,
+		dedup: &dedupState{seen: make(map[string]float64)},
+	}
+
+	// Fill up the map with old entries
+	for i := 0; i < 5001; i++ {
+		c.dedup.seen["cam-001|person"] = float64(i * 10)
+	}
+	// Trigger cleanup by adding a new entry
+	c.isDuplicate("cam-001", "person", 99999.0)
+
+	if len(c.dedup.seen) > 5000 {
+		t.Errorf("dedup map should be cleaned up, got %d entries", len(c.dedup.seen))
+	}
+}
+
+func TestMustUUID(t *testing.T) {
+	u1 := mustUUID()
+	u2 := mustUUID()
+	if u1 == u2 {
+		t.Error("UUIDs should be unique")
+	}
+	// Check format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx (32 hex chars with dashes)
+	parts := 0
+	for _, c := range u1 {
+		if c == '-' {
+			parts++
+		}
+	}
+	if parts != 4 {
+		t.Errorf("UUID format: expected 4 dashes, got %d", parts)
+	}
+}