fix(auth): unmount the module's build-time oidc mount before Redis mount

nuxt-oidc-auth registers its own 'oidc' storage mount at build, so
storage.mount('oidc', …) at runtime threw 'already mounted at oidc:' and
crash-looped the new pods. Unmount the memory mount first.

apps/portal/server/plugins/session-storage.ts

@@ -10,10 +10,14 @@
 // portal-secrets). Unset in dev → in-memory mount stays, no Redis needed.
 import redisDriver from 'unstorage/drivers/redis'
 
-export default defineNitroPlugin(() => {
+export default defineNitroPlugin(async () => {
   const url = process.env.SESSION_REDIS_URL
   if (!url) return
-  useStorage().mount(
+  const storage = useStorage()
+  // The module ships its own build-time 'oidc' mount (memory driver) — it
+  // must be unmounted first or mount() throws 'already mounted at oidc:'.
+  await storage.unmount('oidc')
+  storage.mount(
     'oidc',
     redisDriver({
       url,