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/control/heartbeat_test.go

@@ -0,0 +1,96 @@
+package control
+
+import (
+	"testing"
+)
+
+func TestParseNpuSmiOutput(t *testing.T) {
+	common := `Temperature(C)            : 46
+Aicore Usage Rate(%)      : 25
+Memory Usage Rate(%)      : 86`
+	memory := `Capacity(MB)              : 3513`
+
+	stats := parseNpuSmiOutput(common, memory)
+	if stats == nil {
+		t.Fatal("expected non-nil stats")
+	}
+	if stats.TempC != 46 {
+		t.Errorf("temp: got %d want 46", stats.TempC)
+	}
+	if stats.UtilPct != 25 {
+		t.Errorf("util: got %d want 25", stats.UtilPct)
+	}
+	if stats.MemTotalMB != 3513 {
+		t.Errorf("mem_total: got %d want 3513", stats.MemTotalMB)
+	}
+	if stats.MemPct != 86 {
+		t.Errorf("mem_pct: got %d want 86", stats.MemPct)
+	}
+	// 3513 * 86 / 100 = 3021
+	if stats.MemUsedMB != 3021 {
+		t.Errorf("mem_used: got %d want 3021", stats.MemUsedMB)
+	}
+}
+
+func TestParseInfluxLine(t *testing.T) {
+	line := "npu_status,device=0 temp=46,utilization=0,memory_used=3021,memory_total=3513"
+	stats := parseInfluxLine(line)
+	if stats == nil {
+		t.Fatal("expected non-nil stats")
+	}
+	if stats.TempC != 46 {
+		t.Errorf("temp: got %d want 46", stats.TempC)
+	}
+	if stats.UtilPct != 0 {
+		t.Errorf("util: got %d want 0", stats.UtilPct)
+	}
+	if stats.MemUsedMB != 3021 {
+		t.Errorf("mem_used: got %d want 3021", stats.MemUsedMB)
+	}
+	if stats.MemTotalMB != 3513 {
+		t.Errorf("mem_total: got %d want 3513", stats.MemTotalMB)
+	}
+}
+
+func TestParseInfluxLineInvalid(t *testing.T) {
+	// Input with no space-separated fields returns nil
+	stats := parseInfluxLine("garbage")
+	if stats != nil {
+		t.Error("expected nil stats for garbage input without fields")
+	}
+
+	// Input with fields but no valid data returns zero-valued stats
+	stats2 := parseInfluxLine("npu_status,device=0 ")
+	if stats2 == nil {
+		t.Fatal("expected non-nil stats for input with fields")
+	}
+	if stats2.TempC != 0 || stats2.UtilPct != 0 {
+		t.Errorf("expected zero values, got temp=%d util=%d", stats2.TempC, stats2.UtilPct)
+	}
+}
+
+func TestExtractLastNumber(t *testing.T) {
+	tests := []struct {
+		input string
+		want  int
+	}{
+		{"Temperature(C)            : 46", 46},
+		{"Aicore Usage Rate(%)      : 25%", 25},
+		{"  86%", 86},
+		{"no numbers here", 0},
+		{"", 0},
+		{"value: 123C", 123},
+	}
+	for _, tt := range tests {
+		got := extractLastNumber(tt.input)
+		if got != tt.want {
+			t.Errorf("extractLastNumber(%q) = %d, want %d", tt.input, got, tt.want)
+		}
+	}
+}
+
+func TestInMaintenanceWindow(t *testing.T) {
+	// Can't test specific hours without mocking time.Time,
+	// but verify it doesn't panic
+	_ = inMaintenanceWindow()
+}