Prioritize pending interactions over background activity

[ariofrio]

Summary

• Treat a pending question or approval as Idle even when that thread has a running background command.
• Keep the root Active when another thread in its hierarchy is still working.
• Document the precedence rule and add a patch changeset.

Evidence

• npm run release:check
• Repository tests and layout, vendored UI, and heading-icon checks
• Thread Stages reloaded successfully from the feature worktree

_{Written by Codex}