feat: add mTLS client certificate support

[zero-custom]

• Add ClientCertificate message in config.proto (field 23)
• Add BuildClientCertificates() method in config.go
• Add GetClientCertificate callback in GetTLSConfig()
• Add uTLS adapter in copyConfig() for client cert support
• Support both file path and inline PEM formats

{
  "outbounds": [
    {
      "tag": "vless-mtls",
      "protocol": "vless",
      "settings": {
        "vnext": [
          {
            "address": "mtls.example.com",
            "port": 443,
            "users": [
              {
                "id": "bcrn6-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
                "flow": "",
                "encryption": "none"
              }
            ]
          }
        ]
      },
      "streamSettings": {
        "network": "ws",
        "security": "tls",
        "tlsSettings": {
          "serverName": "mtls.example.com",
          "clientCertificate": [
            {
              "certificateFile": "/path/to/client.crt",
              "keyFile": "/path/to/client.key"
            }
          ]
        },
        "wsSettings": {
          "path": "/vless"
        }
      }
    },
  ]
}

[RPRX]

这个为啥直接关了，有人想双向认证的话就让他弄吧

[Fangliding]

这个为啥直接关了，有人想双向认证的话就让他弄吧

写的是个错的啊 infra都没改 纯AI乱写

[zero-custom]

确实是使用AI生成的，当时是先生成的patch，本地编译了，测试过功能后，让AI合并上传的代码