feat(client/macos): 主 app VPN 接线编译通过 — VpnChannel 入 Runner target

- VpnChannel.swift 加入 Runner target(Compile Sources)
- Logger→NSLog(Runner 部署目标 10.15,os.Logger 需 11)+ 去掉未用的
  SystemExtensions import
- 至此原生 VPN 控制链路全编译通过:主 app(NETunnelProviderManager 启停/
  状态)+ 扩展(libbox)。kUseNativeVpnMacOS 仍 false(待隧道能跑切换)。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/macos/Runner.xcodeproj/project.pbxproj

@@ -37,6 +37,7 @@
 		A17B79FC2FE526F5001ABF28 /* SystemConfiguration.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = A17B79FB2FE526F5001ABF28 /* SystemConfiguration.framework */; };
 		A17B79FE2FE52708001ABF28 /* AppKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = A17B79FD2FE52708001ABF28 /* AppKit.framework */; };
 		A17B7A002FE52723001ABF28 /* libresolv.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = A17B79FF2FE52715001ABF28 /* libresolv.tbd */; };
+		A17B7A072FE52A10001ABF28 /* VpnChannel.swift in Sources */ = {isa = PBXBuildFile; fileRef = A17B7A062FE52A10001ABF28 /* VpnChannel.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -127,6 +128,7 @@
 		A17B79FB2FE526F5001ABF28 /* SystemConfiguration.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SystemConfiguration.framework; path = System/Library/Frameworks/SystemConfiguration.framework; sourceTree = SDKROOT; };
 		A17B79FD2FE52708001ABF28 /* AppKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = AppKit.framework; path = System/Library/Frameworks/AppKit.framework; sourceTree = SDKROOT; };
 		A17B79FF2FE52715001ABF28 /* libresolv.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libresolv.tbd; path = usr/lib/libresolv.tbd; sourceTree = SDKROOT; };
+		A17B7A062FE52A10001ABF28 /* VpnChannel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VpnChannel.swift; sourceTree = "<group>"; };
 		B21E68FC1F5D33DD67A0DF5E /* Pods-RunnerTests.profile.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RunnerTests.profile.xcconfig"; path = "Target Support Files/Pods-RunnerTests/Pods-RunnerTests.profile.xcconfig"; sourceTree = "<group>"; };
 		C55C525CAAF7B3313B74AC65 /* Pods-Runner.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.release.xcconfig"; path = "Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"; sourceTree = "<group>"; };
 		C57BBFD43F9175D1E23685EF /* Pods-RunnerTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RunnerTests.debug.xcconfig"; path = "Target Support Files/Pods-RunnerTests/Pods-RunnerTests.debug.xcconfig"; sourceTree = "<group>"; };
@@ -249,6 +251,7 @@
 		33FAB671232836740065AC1E /* Runner */ = {
 			isa = PBXGroup;
 			children = (
+				A17B7A062FE52A10001ABF28 /* VpnChannel.swift */,
 				33CC10F02044A3C60003C045 /* AppDelegate.swift */,
 				33CC11122044BFA00003C045 /* MainFlutterWindow.swift */,
 				33E51913231747F40026EE4D /* DebugProfile.entitlements */,
@@ -561,6 +564,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				A17B7A072FE52A10001ABF28 /* VpnChannel.swift in Sources */,
 				33CC11132044BFA00003C045 /* MainFlutterWindow.swift in Sources */,
 				33CC10F12044A3C60003C045 /* AppDelegate.swift in Sources */,
 				335BBD1B22A9A15E00E9071D /* GeneratedPluginRegistrant.swift in Sources */,

client/macos/Runner/VpnChannel.swift

@@ -12,10 +12,9 @@
 
 import FlutterMacOS
 import NetworkExtension
-import SystemExtensions
-import os
 
-private let log = Logger(subsystem: "com.pangolin.pangolin", category: "vpn")
+// NSLog 兼容老部署目标(Runner < macOS 11,os.Logger 不可用)。
+private func vpnLog(_ message: String) { NSLog("[pangolin/vpn] %@", message) }
 
 final class VpnChannel: NSObject {
     private static let tunnelBundleId = "com.pangolin.pangolin.PacketTunnel"
@@ -76,7 +75,7 @@ final class VpnChannel: NSObject {
             ])
             result(nil)
         } catch {
-            log.error("start failed: \(error.localizedDescription)")
+            vpnLog("start failed: \(error.localizedDescription)")
             result(FlutterError(code: "start_failed", message: error.localizedDescription, details: nil))
         }
     }