[Bug]: OIDC With Entra Not Authenticating Additional Users

### Verified issue does not already exist?

- [x] I have searched and found no existing issue

### What happened?

I have configured OIDC with an app registration in Entra and it is working fine to authenticate the account set as server owner. Whenever I authentication a second user (already added under User Directory) it throws "openid-grant-failed". The journal is linked below for review, most relevant line reads **OAuth2 Authorization code was already redeemed, please retry with a new valid code or use an existing refresh token**. The sign-in logs Entra-side show successful authentication. I also noticed that when I authenticated my account with OIDC, it set my username in User Directory as some sort of guid:

Log: https://pastebin.com/YeWFFVUJ

### How can we reproduce the issue?

Actual is being hosted on a home server running Debian 12. Entra is set up as IdP using an App Registration.

### Where are you hosting Actual?

Locally via Yarn

### What browsers are you seeing the problem on?

Chrome

### Operating System

Windows 11

Start with the OIDC sign-in flow using the Entra app registration and compare the server-owner and additional-user paths; review the linked journal for the authorization-code redemption failure. Reproduce locally via Yarn on Debian 12, then verify that a second User Directory account authenticates without openid-grant-failed and that its username mapping is handled consistently.

Scritto dal modello di indicizzazione a partire dal testo della issue.