fix(streams): tighten stream typings and guard optional runtime paths for duplex and wrapper utilities

test/test.streamwrapper.ts

@@ -1,4 +1,4 @@
-import { expect, tap } from '@push.rocks/tapbundle';
+import { expect, tap } from '@git.zone/tstest/tapbundle';
 import * as fs from 'fs';
 import { StreamWrapper, SmartDuplex } from '../ts/index.js';
 
@@ -27,7 +27,8 @@ tap.test('StreamWrapper: should propagate errors', async (tools) => {
     await wrapper.run();
   } catch (err) {
     errorCaught = true;
-    expect(err.message).toEqual('intentional error');
+    const message = err instanceof Error ? err.message : String(err);
+    expect(message).toEqual('intentional error');
   }
   expect(errorCaught).toBeTrue();
 });