[AI] Expand Test Coverage - portals/portal-stream

[KCarretto]

This PR systematically increases test coverage for the implants/lib/portals/portal-stream module, specifically targeting the PayloadSequencer and OrderedWriter.

Key improvements:

• Added new_tcp_mote and new_udp_mote tests to test_sequencer.
• Expanded test_writer to include write_tcp and write_udp operations. Refactored the internal output capture to use Arc<Mutex<Vec<Mote>>> to bypass borrow checker limitations.
• Introduced a conditionally compiled asynchronous test suite (test_writer_async) utilizing tokio to verify write_bytes_async, write_tcp_async, and write_udp_async.

These changes increased overall line coverage for the module from 68.70% to 95.87%. Tests have been validated for stability by running them sequentially 20 times with and without the tokio feature flag.

---

PR created automatically by Jules for task 17804473834142346225 started by @KCarretto

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.

[github-actions]

Summary

Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
2836    ±0	2836    ±0	0    ±0	0    ±0	0    ±0	0    ±0	1ms    ±0

Previous Results

Build 🏗️	Result 🧪	Tests 📝	Passed ✅	Failed ❌	Skipped ⏭️	Other ❓	Flaky 🍂	Duration ⏱️
#1812	✅	2836	2836	0	0	0	0	37.3s

Insights

Average Tests per Run	Total Flaky Tests	Total Failed	Slowest Test (p95)
2836	0	0	5.9s

Slowest Tests

Test 📝	Results 📊	Duration (avg) ⏱️	Duration (p95) ⏱️
TestDockerExecutor_Build_ContextCancellation	1	5.9s	5.9s
eldritch-libsys: std::dll_inject_impl::tests::test_dll_inject_simple	1	5.2s	5.2s
TestInteractiveShell	1	5.0s	5.0s
TestOtherStreamOutput	1	5.0s	5.0s
imix::bin/imix: install::tests::test_install_execution	3	1.8s	5.0s
imix::bin/imix: install::tests::test_install_execution	3	1.8s	5.0s
imix::bin/imix: install::tests::test_install_execution	3	1.8s	5.0s
TestDockerExecutor_Build_SimpleEcho	1	4.0s	4.0s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.0s
imix::bin/imix: tests::task_tests::test_task_streaming_output	3	3.0s	3.0s

_{🎉 No failed tests in this run. | 🍂 No flaky tests in this run.}

Github Test Reporter by CTRF 💚