feat(core): add hasCoordinatorConnection and onError to transport

Expose coordinator liveness on MeshTransport so consumers can degrade
gracefully. Add optional onError to TransportEvents for non-fatal
error reporting. Reduce connect timeout from 2s to 1s to avoid
blocking startup on orphan coordinator ports.

Author: Mearman

src/core/tcp-transport.ts

@@ -34,7 +34,7 @@ import { nanoid } from "./nanoid.js";
 const COORDINATOR_HOST = "127.0.0.1";
 
 /** Timeout for connecting to the coordinator before giving up. */
-const CONNECT_TIMEOUT_MS = 2000;
+const CONNECT_TIMEOUT_MS = 1000;
 
 // ---------------------------------------------------------------------------
 // Async socket write helper (not exported)
@@ -132,6 +132,12 @@ export class TcpTransport implements MeshTransport {
     return this._isCoordinator;
   }
 
+  get hasCoordinatorConnection(): boolean {
+    return (
+      this.coordinatorSocket !== undefined && !this.coordinatorSocket.destroyed
+    );
+  }
+
   // -----------------------------------------------------------------------
   // MeshTransport — Data server
   // -----------------------------------------------------------------------

src/core/tls-transport.ts

@@ -35,7 +35,7 @@ import { nanoid } from "./nanoid.js";
 // ---------------------------------------------------------------------------
 
 const COORDINATOR_HOST = "127.0.0.1";
-const CONNECT_TIMEOUT_MS = 2000;
+const CONNECT_TIMEOUT_MS = 1000;
 
 /**
  * Wrap tls.createServer with a retry for intermittent OpenSSL ASN.1 races
@@ -161,6 +161,12 @@ export class TlsTransport {
     return this._isCoordinator;
   }
 
+  get hasCoordinatorConnection(): boolean {
+    return (
+      this.coordinatorSocket !== undefined && !this.coordinatorSocket.destroyed
+    );
+  }
+
   // -----------------------------------------------------------------------
   // TLS options
   // -----------------------------------------------------------------------

src/core/transport.ts

@@ -68,6 +68,11 @@ export interface TransportEvents {
    */
   onPeerDisconnected(handle: ConnectionHandle): void;
 
+  /**
+   * A non-fatal error occurred that consumers should know about.
+   */
+  onError?(error: Error): void;
+
   /**
    * A peer introduced itself to the coordinator.
    * Only fires on the coordinator instance.
@@ -123,6 +128,9 @@ export interface MeshTransport {
   /** Whether this instance is the mesh coordinator. */
   readonly isCoordinator: boolean;
 
+  /** Whether this instance has a live connection to a coordinator. */
+  readonly hasCoordinatorConnection: boolean;
+
   /**
    * Start the data server on an OS-assigned port.
    * Resolves when the server is listening.

src/core/ws-transport.ts

@@ -109,6 +109,10 @@ export class WebSocketTransport implements MeshTransport {
     return this._isCoordinator;
   }
 
+  get hasCoordinatorConnection(): boolean {
+    return this.coordinatorWs?.readyState === WebSocket.OPEN;
+  }
+
   // -----------------------------------------------------------------------
   // MeshTransport — Data server
   // -----------------------------------------------------------------------