Add a reusable LoadingOverlay component that dims and disables the
container owning an in-flight action, with a spinning indicator and
label. Apply it to:
- SessionCard (when actionBusyId matches)
- InstanceList cards (per busyInstanceId with action-specific labels)
- CreateSessionForm (while submitting)
- ToolStarter (while starting)
Also add .icon-spin animation and position:relative to the relevant
containers.
Quality gates: npm run typecheck, npm run lint, npm test -- --run
(87 passed).
Developer