add root loading.tsx skeleton (B5 mirror)
- Add the root /platform/admin/loading.tsx — covers all 73 SaaS tenant
- dashboard pages via Next.js route-level Suspense streaming.
- Before: every /platform/admin/* navigation blocked until the layout
- finished resolving auth + tenant context + entitlements (~150-400ms).
- After: the skeleton renders instantly, server data streams in when
- ready. Eliminates the perceived 'click → freeze → page' delay.
- Mirrors the B5 work that landed for /admin (commit 49c10ad6 + 24ffe657).
- Sidebar + header still render from the layout; only the inner page
- content shows the skeleton until data arrives.
101837cView on GitHub →