Review follow-ups on the refused-creation notice:
- `openWorkspace` raises `createFailed` only while its navigation is
current, so a refusal that lands after a later navigation or owner
disposal stays silent — the gate `initializeDefaultWorkspace` already
uses and what the README states; two service cases pin it.
- `RowActionToast` switches on the closed notice union and ends in
`assertNever`, so an unhandled kind fails to compile instead of
rendering another notice's copy.
- `apps/web/tests/new-session-refused.e2e.ts` drives the composed Web
server with a user preset whose row cannot resolve and compares the
notice's ARIA golden, beside the default-Workspace failure scenario.
- `@throws` on `openWorkspace` covers every failure (catalog
regenerated); `RowToast.createFailed` records why the Host code stays
in the copy; the README states that other failures show their own
message.