feat(portal): real Security & audit page (+ bundled Storage / per-tenant-roles WIP)

Security & audit (admin)
- Audit log: real, tenant-scoped — widened GET /tenants/:slug/audit with
  q/action/outcome/actorEmail/since/before; UI gains search, outcome + time
  filters, action chips, cursor pagination, and client-side CSV export.
- Security policy: new tenant.securityPolicy (mfaMode, session idle/absolute,
  allowedCountries, ipAllowlist) + PATCH /tenants/:slug/security-policy
  (membership-gated, audited). Editable, labelled by enforcement status.
- MFA: live enrollment overview via GET /tenants/:slug/mfa-status
  (Authentik countAuthenticators per member).
- SSO apps (Dezky as IdP): real Authentik OIDC provider + application CRUD,
  scoped to the tenant group. New AuthentikClient methods (provider/app/binding
  + flow/key/scope discovery), TenantSsoApp schema, TenantSsoService (rollback
  on partial failure; client secret never stored), GET/POST/DELETE
  /tenants/:slug/sso-apps. Validated end-to-end against live Authentik.
- Deferred: shared-flow MFA/geo/session enforcement (global auth-flow blast
  radius) — to be done as its own reviewed change.

Bundled in-progress work that shares the same files (kept together so the tree
stays green):
- Storage page: StorageService + GET /tenants/:slug/storage (OCIS-backed),
  storage.get proxy, storage.vue.
- Per-tenant roles: User.tenantRoles + MeProfile.tenantRoles plumbing.

apps/portal/server/api/tenants/[slug]/sso-apps/[id].delete.ts

@@ -0,0 +1,20 @@
+// Remove an SSO app. Proxies DELETE /tenants/:slug/sso-apps/:id; platform-api
+// deletes the Authentik application + provider and enforces tenant membership.
+
+import { getUserSession } from 'nuxt-oidc-auth/runtime/server/utils/session.js'
+
+export default defineEventHandler(async (event) => {
+  const session = await getUserSession(event).catch(() => null)
+  const accessToken = (session as { accessToken?: string } | null)?.accessToken
+  if (!accessToken) {
+    throw createError({ statusCode: 401, statusMessage: 'Not signed in' })
+  }
+  const slug = getRouterParam(event, 'slug')
+  const id = getRouterParam(event, 'id')
+  const base = process.env.PLATFORM_API_INTERNAL_URL ?? 'http://platform-api:3001'
+  await $fetch(`${base}/tenants/${slug}/sso-apps/${id}`, {
+    method: 'DELETE',
+    headers: { Authorization: `Bearer ${accessToken}` },
+  })
+  return { ok: true }
+})