feat(server): unify WireGuard into the shared server transport pipeline

ts/smartvpn.interfaces.ts

@@ -96,12 +96,15 @@ export interface IVpnServerConfig {
   defaultRateLimitBytesPerSec?: number;
   /** Default burst size for new clients (bytes). Omit for unlimited. */
   defaultBurstBytes?: number;
-  /** Transport mode: 'both' (default, WS+QUIC), 'websocket', 'quic', or 'wireguard' */
-  transportMode?: 'websocket' | 'quic' | 'both' | 'wireguard';
+  /** Transport mode: 'all' (default, WS+QUIC+WG if configured), 'both' (WS+QUIC),
+   *  'websocket', 'quic', or 'wireguard' */
+  transportMode?: 'websocket' | 'quic' | 'both' | 'all' | 'wireguard';
   /** QUIC listen address (host:port). Defaults to listenAddr. */
   quicListenAddr?: string;
   /** QUIC idle timeout in seconds (default: 30) */
   quicIdleTimeoutSecs?: number;
+  /** WireGuard: server X25519 private key (base64). Required when transport includes WG. */
+  wgPrivateKey?: string;
   /** WireGuard: UDP listen port (default: 51820) */
   wgListenPort?: number;
   /** WireGuard: configured peers */
@@ -171,6 +174,8 @@ export interface IVpnClientInfo {
   registeredClientId: string;
   /** Real client IP:port (from PROXY protocol or direct TCP connection) */
   remoteAddr?: string;
+  /** Transport used: "websocket", "quic", or "wireguard" */
+  transportType: string;
 }
 
 export interface IVpnServerStatistics extends IVpnStatistics {