chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/client/src/errors.ts

@@ -0,0 +1,34 @@
+import type { ProtocolError, ProtocolErrorCode } from "@earendil-works/pi-protocol";
+
+export class ServerError extends Error {
+	readonly code: ProtocolErrorCode;
+
+	constructor(error: ProtocolError) {
+		super(error.message);
+		this.name = "ServerError";
+		this.code = error.code;
+	}
+}
+
+export class DisconnectedError extends Error {
+	constructor(message = "Client is disconnected", cause?: Error) {
+		super(message, cause === undefined ? undefined : { cause });
+		this.name = "DisconnectedError";
+	}
+}
+
+export class ClientDisposedError extends Error {
+	constructor() {
+		super("Client is disposed");
+		this.name = "ClientDisposedError";
+	}
+}
+
+export function toError(error: unknown): Error {
+	return error instanceof Error ? error : new Error(String(error));
+}
+
+export function toDisconnectedError(error: unknown): DisconnectedError {
+	const cause = toError(error);
+	return cause instanceof DisconnectedError ? cause : new DisconnectedError(cause.message, cause);
+}