💥 feat(agent)!: 添加主机监控代理首版

* 实现周期采集、快照缓存、本地 HTTP API 和主动上报

* 补齐 Linux 和 Windows 主机、网络、资源、进程和 TCP 采集

* 添加服务生命周期管理、配置加载、构建脚本和测试覆盖

BREAKING CHANGE: network.ips 拆分为 network.ipv4s 和 network.ipv6s。

internal/service/service.go

@@ -0,0 +1,26 @@
+package service
+
+import "mfd-monitor-agent/internal/config"
+
+// InstallOptions carries platform-specific service installation inputs.
+type InstallOptions struct {
+	// ConfigPath is preserved in the service command line when a config file was supplied.
+	ConfigPath string
+}
+
+// Manager controls operating system service installation and lifecycle commands.
+type Manager interface {
+	// Install registers the agent executable as an operating system service.
+	Install(executable string, cfg config.Config, opts InstallOptions) error
+	// Uninstall removes the operating system service registration.
+	Uninstall(cfg config.Config) error
+	// Start asks the operating system service manager to start the agent service.
+	Start(cfg config.Config) error
+	// Stop asks the operating system service manager to stop the agent service.
+	Stop(cfg config.Config) error
+}
+
+// NewManager returns the platform-specific service manager.
+func NewManager() Manager {
+	return newManager()
+}