fix(client/macos): P1 骨架修正 — bundle id 统一 PacketTunnel + Info.plist 精简

- VpnChannel/Provider: 扩展 bundle id 统一为 com.pangolin.pangolin.PacketTunnel
  (对齐 Xcode 新建 target 的实际 id)
- PacketTunnel/Info.plist: 去掉重复 CFBundlePackageType + 多余 NEMachServiceName,
  只保留 NEProviderClasses(其余标准键由 GENERATE_INFOPLIST_FILE 合并)
- .gitignore: 忽略 Frameworks/Libbox.xcframework(204MB,build-libbox.sh 产出)

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

client/macos/Runner/VpnChannel.swift

@@ -18,7 +18,7 @@ import os
 private let log = Logger(subsystem: "com.pangolin.pangolin", category: "vpn")
 
 final class VpnChannel: NSObject {
-    private static let tunnelBundleId = "com.pangolin.pangolin.tunnel"
+    private static let tunnelBundleId = "com.pangolin.pangolin.PacketTunnel"
 
     private var statusSink: FlutterEventSink?
     private var statsSink: FlutterEventSink?