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/pages/partner/customers.vue

@@ -9,6 +9,7 @@ import type { CustomerOrg, CustomerStatus, PartnerTenantDoc } from '~/types/part
 
 const toast = useToast()
 const router = useRouter()
+const { request } = useApiFetch()
 const partnerMode = usePartnerMode()
 
 const view = ref<'table' | 'cards'>('table')
@@ -181,7 +182,7 @@ async function saveEdit() {
   }
   savingEdit.value = true
   try {
-    await $fetch(`/api/partner/tenants/${editCustomer.value.slug}`, {
+    await request(`/api/partner/tenants/${editCustomer.value.slug}`, {
       method: 'PATCH',
       body: {
         name: editForm.name,
@@ -204,7 +205,7 @@ async function saveEdit() {
 async function toggleSuspend(c: CustomerRow) {
   const action = c.status === 'suspended' ? 'resume' : 'suspend'
   try {
-    await $fetch(`/api/partner/tenants/${c.slug}/${action}`, { method: 'POST' })
+    await request(`/api/partner/tenants/${c.slug}/${action}`, { method: 'POST' })
     toast.ok(action === 'suspend' ? 'Suspended' : 'Resumed', c.name)
     editCustomer.value = null
     await refreshAll()