feat: 支持 Windows x86_64 平台编译

- 新增 WinTun TUN 设备实现(tun_windows.go),无需安装驱动,
  wintun.dll 嵌入 exe 运行时自动释放
- 新增 Windows 路由管理(route_windows.go),使用 route/netsh 命令
- 新增 Windows 路径(paths_windows.go),使用 %APPDATA%/%LOCALAPPDATA%
- 拆分 daemon 启动逻辑:launch_unix.go(Setsid) / launch_windows.go
  (CREATE_NEW_PROCESS_GROUP),公共代码提取到 launch_common.go
- 拆分提权逻辑:elevation_darwin.go(osascript) / elevation_windows.go
  (ShellExecute UAC) / elevation_other.go(pkexec)
- IPCSocketPath 按平台分散,Windows 用 %TEMP%\lmvpn.sock
- daemon 二进制名用编译时常量(daemonBinaryName),按平台选定 .exe 后缀
- Makefile 新增 build-windows 目标
- 重新标记 !darwin 文件为 !darwin && !windows

internal/paths/paths.go

@@ -57,6 +57,4 @@ func LogFile() string { return Paths.Log + "/lmvpn.log" }
 // DaemonLogFile returns the path to the daemon log file.
 func DaemonLogFile() string { return Paths.Log + "/lmvpn-daemon.log" }
 
-// IPCSocketPath returns the path to the unix domain socket used for
-// GUI <-> daemon communication.
-func IPCSocketPath() string { return "/tmp/lmvpn.sock" }
+

internal/paths/paths_darwin.go

@@ -7,6 +7,10 @@ import (
 	"path/filepath"
 )
 
+// IPCSocketPath returns the path to the unix domain socket used for
+// GUI <-> daemon communication.
+func IPCSocketPath() string { return "/tmp/lmvpn.sock" }
+
 func init() {
 	home, _ := os.UserHomeDir()
 	recomputePaths(home)

internal/paths/paths_other.go

@@ -1,4 +1,4 @@
-//go:build !darwin
+//go:build !darwin && !windows
 
 package paths
 
@@ -7,6 +7,10 @@ import (
 	"path/filepath"
 )
 
+// IPCSocketPath returns the path to the unix domain socket used for
+// GUI <-> daemon communication.
+func IPCSocketPath() string { return "/tmp/lmvpn.sock" }
+
 func init() {
 	home, _ := os.UserHomeDir()
 	recomputePaths(home)

internal/paths/paths_windows.go

@@ -0,0 +1,42 @@
+//go:build windows
+
+package paths
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// IPCSocketPath returns the path to the unix domain socket used for
+// GUI <-> daemon communication. On Windows 10 1803+ AF_UNIX is
+// supported; the socket is placed in the user's temp directory.
+func IPCSocketPath() string {
+	return filepath.Join(os.TempDir(), "lmvpn.sock")
+}
+
+func init() {
+	home, _ := os.UserHomeDir()
+	recomputePaths(home)
+}
+
+// recomputePaths sets Paths based on the given home directory.
+// On Windows the layout follows platform conventions:
+//
+//	%APPDATA%\<BundleID>\      data (db, config)
+//	%LOCALAPPDATA%\<BundleID>\ cache
+//	%LOCALAPPDATA%\<BundleID>\Logs\  logs
+func recomputePaths(home string) {
+	appData := os.Getenv("APPDATA")
+	if appData == "" {
+		appData = filepath.Join(home, "AppData", "Roaming")
+	}
+	localAppData := os.Getenv("LOCALAPPDATA")
+	if localAppData == "" {
+		localAppData = filepath.Join(home, "AppData", "Local")
+	}
+	Paths = Dirs{
+		Data:  filepath.Join(appData, BundleID),
+		Cache: filepath.Join(localAppData, BundleID),
+		Log:   filepath.Join(localAppData, BundleID, "Logs"),
+	}
+}