emit Error objects from socket 'error' events

main tightened the socket error contract to pass an Error (see
types/modules/networking.d.ts, which documents the reason as
`error.message`); the epoxy rewrite still emitted a bare string,
matching the older `(reason: string)` declaration.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/puter-js/src/modules/networking/PSocket.js

@@ -19,12 +19,12 @@ function normalizeWriteData (data) {
     throw new Error('Invalid data type (not TypedArray, ArrayBuffer or String).');
 }
 
-function normalizeErrorReason (reason) {
+function normalizeError (reason) {
     if ( reason instanceof Error ) {
-        return reason.message;
+        return reason;
     }
 
-    return String(reason);
+    return new Error(String(reason));
 }
 
 export class PSocket extends EventListener {
@@ -236,7 +236,7 @@ export class PSocket extends EventListener {
             return;
         }
 
-        this.emit('error', normalizeErrorReason(reason));
+        this.emit('error', normalizeError(reason));
         this.#closing = true;
         void this.#closeStreams(true);
     }