Background sessions with interactive messages don't appear in /resume

Bug

Sessions started as background jobs that subsequently receive interactive user messages
don't appear in the /resume session list. The user has to know the job ID and navigate
to ~/.claude/jobs/ manually.

Expected behavior

If a session tagged as a background job receives direct interactive messages from the user,
it should appear in /resume alongside normal interactive sessions — or at minimum,
/resume should have a flag to include background sessions (/resume --all).

Repro

1. Start a session that gets spawned as a background job (e.g., continuation after context

compaction, or a job that the user then chats with directly)

1. Work interactively in that session for an extended period
2. Close the session
3. Run /resume — the session doesn't appear in the list

Workaround

Navigate to ~/.claude/jobs/{job-id} directly.