Keep unanswered native questions answerable after server restart #20235

Reproduced on the current desktop release, with the same result as the original post.

Version: desktop 0.1.1, macOS arm64. The blocking clause in RestartContinuation.ts is unchanged on main @ 8d3b061. Claude provider, "Continue threads after restarts" at its default (on).

In real use: a desktop update restarted the server while 8 runs were active. 6 were continued. The 2 that were waiting on AskUserQuestion were not. Their requests became expired / not_resumable ("The server restarted before this runtime request was resolved."). I only noticed later and had to nudge each thread by hand to get the question asked again.

Isolated repro (separate --base-dir, single server):

1. Ask Claude to call AskUserQuestion. The card shows, and the sidebar shows "Input".
2. Stop the server with SIGTERM and start it again.
3. Reopen the thread.

Result: the request is cancelled / not_resumable ("Provider session was closed before this runtime request was resolved."). The run is cancelled and no continuation is sent. The question card and the "Input" badge are gone. The thread shows "Worked for 26s" and a normal composer, with no notice that a question was lost. Only a collapsed "Input requested" row is left in the work log.

Before the restart:

After the restart:

Not continuing matches #18461 and docs/user/updating.md ("A thread is not resumed while it waits for your answer"). But after the restart the thread no longer shows that it waits for an answer, so from the sidebar it looks finished. The direction proposed here, keeping the durable question answerable through the message-response path without continuing past it, would fix exactly this. If that scope is too large, a smaller step would be to keep the thread marked as needing input, with a notice that the question expired.

Investigated with Claude Opus 5.5 in Claude Code.

Closing: current main already covers this as of 867112cda0. If you still see it on a build that includes that commit, reply and we'll reopen.