[BUG] VS Code Codex thread hangs during web/tool search and UI loses recent messages

What issue are you seeing?

In VS Code Codex, the thread hung while the assistant was doing web/tool search. After that, the UI appeared to lose the latest part of the conversation and only showed the beginning of the thread.

The session data was not fully lost: the missing turns were still present in the local session JSONL under ~/.codex/sessions/..., so this looks like a UI restore/reconnect/history rendering bug rather than total data loss.

I also hit a separate recurring compact error in the same environment:

Error running remote compact task: stream disconnected before completion: error sending request for url (https://chatgpt.com/backend-api/codex/responses/compact)

What steps can reproduce the bug?

1. Use Codex in VS Code on macOS.
2. Continue a long-running thread.
3. Let Codex perform web/tool work for a while.
4. The thread hangs.
5. After the hang/reconnect, the UI no longer shows the latest messages, but the missing content still exists in ~/.codex/sessions/...jsonl.

What is the expected behavior?

The thread should recover cleanly after hangs/tool failures, and the UI should restore the full recent conversation instead of dropping the latest visible turns.

Additional information

• Platform: macOS
• Surface: VS Code Codex extension
• Session evidence recovered from local session file
• Related local artifacts:
• ~/.codex/sessions/2026/04/01/rollout-2026-04-01T10-12-51-019d47e3-494a-7ae1-b05f-622c2cc8e853.jsonl
• ~/Library/Logs/com.openai.codex/2026/04/01/

Notes

The local session file preserved assistant/user messages that the UI no longer displayed, which strongly suggests a restore/rendering/history-sync issue after the hang.