Completes the arcadia-admin operator surface for the integration registry and
the capability/route-guard framework it depends on.
- Integration registry: route + Data-group nav entry + `platform.integrations`
capability; the in-app client now delegates to the shared
`@crema/integration-registry-client` lib (vite alias + tsconfig); the
operator Integrations page (committed earlier) is now reachable.
- Capability gating: capabilities map + route-guard + jwt helpers + the
apps/plan/entitlements routes and supporting tenants/session changes.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>