fix(ci): DB-3 Drift-Check — -c Release war --context Release (DbContext-Name!), nicht Build-Config

dotnet ef interpretiert -c als --context, daher 'No DbContext named Release was found' →
Backend-Tests-Job rot seit DB-3. Korrekt: --configuration Release. Lokal verifiziert:
Release-Build + --no-build --configuration Release → 'No changes'. Tests 140/140.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -59,7 +59,7 @@ jobs:
           dotnet ef migrations has-pending-model-changes
           --project GerbilManagerWebAPI
           --startup-project GerbilManagerWebAPI
-          --no-build -c Release
+          --no-build --configuration Release
 
       - name: Tests ausfuehren
         run: dotnet test GerbilManager.slnx --no-build -c Release --logger "console;verbosity=normal"