feat(portal): customer-admin surface on real data + Stripe billing + session resilience

Access & navigation
- Gate partner-mode strictly to partner staff so admins/end-users never inherit
  leftover partner-view state; purge stale session entry on hydrate.
- Role-driven admin entry: useMe.isTenantAdmin, Admin/Personal tiles in the app
  launcher, and an /admin route guard in the global middleware (fail closed).
- Drop the duplicate user identity block from the sidebar footer.

Admin pages on real data
- New tenant-scoped, membership-gated endpoints: GET /tenants/:slug/{audit,users,
  invoices}; useTenant composable resolves the active workspace + subscription.
- Dashboard: real seats, spend (cycle-normalized + minor-units), plan, renewal,
  and recent audit; unbacked sections removed.
- Users & groups: real members; Groups/Invitations/Service accounts shown as
  honest "coming soon".
- Subscription & invoices: real plan hero, invoice history, and billing details.

Stripe payment method (Elements + SetupIntent)
- StripeClient: publishable key + getDefaultCard/createSetupIntent/setDefaultCard.
- CustomerBillingController + BillingService methods (ensure-customer on demand).
- Portal: PaymentMethodModal, useStripeJs (CDN load), proxies; hidePostalCode.

Editable billing details & whitelabel branding
- PATCH /tenants/:slug/billing-info (narrow: company/VAT/country/email).
- TenantBranding schema/service + GET/PUT /tenants/:slug/branding: real product
  name, accent colour, and per-tenant email-template overrides.
- Branding preview + sidebar workspace mark wired to real name/plan/seats/colour
  with YIQ auto-contrast (readableOn util).

Session resilience
- Request offline_access so Authentik issues a refresh token (automaticRefresh).
- Silent refresh + single retry on 401 for writes (useApiFetch, incl. partner
  pages) and reads (useMe.fetchMe) — no redirect, no lost input.
- Modal backdrop closes only on press+release on the backdrop (no more
  drag-select-to-close).

apps/portal/nuxt.config.ts

@@ -83,7 +83,12 @@ export default defineNuxtConfig({
         // Discovery URL — used by id_token validation to fetch JWKS + issuer
         openIdConfiguration:
           'https://auth.dezky.local/application/o/dezky-portal/.well-known/openid-configuration',
-        scope: ['openid', 'profile', 'email', 'groups'],
+        // offline_access asks Authentik for a refresh token. Without it there's
+        // nothing to refresh with, so session.automaticRefresh can't run and the
+        // module's refresh() falls back to a full login() redirect on token
+        // expiry — yanking the user to the dashboard mid-action and losing their
+        // input. With it, the access token renews silently in the background.
+        scope: ['openid', 'profile', 'email', 'groups', 'offline_access'],
         userNameClaim: 'preferred_username',
         responseType: 'code',
         grantType: 'authorization_code',