Repair LOCATION-A defect where processing feedback rendered near the
completed narrative instead of inside the active follow-up block.
Changes:
- components/reasoning-workspace.jsx: three targeted edits using a single
spinner component with conditional rendering; hasActiveFollowUp routes
ownership to the correct container
- tests/open-questions-vs-assumptions.test.jsx: regression test confirming
exactly one indicator, DOM child of follow-up-block, ownership separation
Accepted criteria met:
✅ Exactly one processing indicator during follow-up processing
✅ Indicator is a DOM child of follow-up-block
✅ Top-level indicator suppressed when follow-up active
✅ Initial answer flow preserved (top-level when no follow-up)
✅ Successful follow-up promotion intact
✅ All existing context retained
✅ No new state/lifecycle changes/error redesign