Adds createScopedClient() — an openapi-fetch client bound to a specific
Instance (rather than the active one in localStorage) — and the
useScoped* TanStack Query hooks (workspaces, peers, peer representation,
peer card) with per-instance query-key isolation so caches never collide
across instances.
Foundation for multi-instance features (seed kits, desktop
auto-discover) that read from non-active instances.
Co-authored-by: Ben Sheridan-Edwards <BenSheridanEdwards@users.noreply.github.com>
