# Backend Fix - Sync Model Changes

## Problem
The backend was failing to start with a `System.InvalidOperationException` because the `ZentralDbContext` model had pending changes that were not captured in a migration.

## Solution
1.  Created a new migration `SyncModelChanges` to synchronize the database schema with the code.
    - Command: `dotnet ef migrations add SyncModelChanges --project Zentral.Infrastructure --startup-project Zentral.API`
2.  Updated the database.
    - Command: `dotnet ef database update --project Zentral.Infrastructure --startup-project Zentral.API`

## Status
- [x] Create Migration
- [x] Update Database
- [x] Verify Backend Startup

The backend now starts correctly and listens on the configured port.