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/reports.vue

@@ -12,6 +12,7 @@ import type { CustomerOrg, CustomerStatus } from '~/types/partner'
 import type { TaskContext } from '~/components/partner/CustomerTaskPanel.vue'
 
 const toast = useToast()
+const { request } = useApiFetch()
 
 // Decorative MRR sparkline shape only — historical MRR isn't stored yet (a
 // daily-snapshot job lands later; see useMrrTrendline). The live numbers
@@ -262,7 +263,7 @@ async function deleteReport() {
     return
   }
   try {
-    await $fetch(`/api/partner/reports/saved/${r.id}`, { method: 'DELETE' })
+    await request(`/api/partner/reports/saved/${r.id}`, { method: 'DELETE' })
     toast.bad('Report deleted', r.name)
     confirmDeleteId.value = null
     await Promise.all([refreshSaved(), refreshNuxtData('partner-reports-saved')])
@@ -284,7 +285,7 @@ async function onCreated(payload: {
   format: string
 }) {
   try {
-    await $fetch('/api/partner/reports/saved', {
+    await request('/api/partner/reports/saved', {
       method: 'POST',
       body: {
         name: payload.name,