- Shared immutable model registries and auth storage via beforeAll/afterAll.
- Swapped fixed-delay settle sleeps for predicate polling and signals.
- Stubbed network/timers to drop wall-clock waits in registry and history tests.
- Added resetDisplay invalidation tests and startup-timing breakdown lines.
- Updated toggleToolOutputExpansion to pass allowUnknownViewportMutation when requesting render.
- Added a test that verifies tool output toggling sets expansion state and calls requestRender with the new flag.
- Documented the Ctrl+O POSIX tool-result expansion scrollback fix in the changelog.