Fix UI flashing from rapid view switching during agent execution #455
Description
Problem
When an agent is actively working, the UI rapidly switches between views and visibly flashes. This creates a jarring experience and makes it hard to follow progress.
Goal
Stabilize the UI so view changes are intentional and non-disruptive while agent tasks are running.
Acceptance Criteria
- No rapid or repeated view-flashing while the agent is executing steps.
- View transitions occur only when state meaningfully changes.
- Agent progress remains visible without abrupt screen switching.
- Add/update test coverage for the view-switching behavior.