fix(cli): 纯参数模式不再静默丢弃 --tunnel-port

build_from_args_only 用 ..Default::default() 填充其余字段，
args.tunnel_port 被丢弃，纯命令行参数模式下隧道端口设置无效。

顺带修复 vnt-ipc feature 下 main_cli.rs 的 clippy never_loop
（此前验证未覆盖该 feature）：loop 两臂都直接 break，去掉 loop。

测试：test_args_only_keeps_tunnel_port 验证参数透传到 Config。

src/args_config.rs

@@ -295,6 +295,7 @@ fn build_from_args_only(args: Args) -> anyhow::Result<(Config, CtrlConfig)> {
         mtu: args.mtu,
         port_mapping: args.port_mapping,
         allow_port_mapping: args.allow_mapping,
+        tunnel_port: args.tunnel_port,
         ..Default::default()
     };
     let ctrl_config = CtrlConfig {
@@ -475,3 +476,26 @@ server = ["quic://1.2.3.4:29872"]
         Ok(())
     }
 }
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// 纯参数模式下 --tunnel-port 不能被静默丢弃
+    #[test]
+    fn test_args_only_keeps_tunnel_port() {
+        let args = Args::try_parse_from([
+            "vnt",
+            "-s",
+            "quic://127.0.0.1:29872",
+            "-n",
+            "test-net",
+            "--tunnel-port",
+            "12345",
+        ])
+        .unwrap();
+        let (config, _) = build_from_args_only(args).unwrap();
+        assert_eq!(config.tunnel_port, Some(12345));
+    }
+}

src/main_cli.rs

@@ -143,16 +143,11 @@ async fn main0() -> anyhow::Result<()> {
             }
         });
     }
-    loop {
-        tokio::select! {
-            _ = network_manager.wait_all_stopped() => {
-                break;
-            }
+    tokio::select! {
+        _ = network_manager.wait_all_stopped() => {}
 
-            _ = tokio::signal::ctrl_c() => {
-                log::info!("Ctrl+c received!");
-                break;
-            }
+        _ = tokio::signal::ctrl_c() => {
+            log::info!("Ctrl+c received!");
         }
     }
     drop(task_group_guard);