pac code push returns internal server error (500) when using service principal authentication

[SergioCantera]

Description

pac code push consistently fails with an internal server error (HTTP 500) when authenticating
via service principal (application ID + client secret). The same command works correctly when
authenticated with a personal user account.

Environment

• PAC CLI version: 2.2.1+g666525f (.NET 10.0.2)
• OS: Windows (GitHub Actions runner: windows-latest)
• Power Platform environment region: EMEA

Steps to reproduce

1. Register the app as a Management Application:
   pac admin application register --application-id
2. Create an Application User in the target environment with System Administrator security role.
3. Authenticate using service principal:
   pac auth create --url https://.crm4.dynamics.com --applicationId --clientSecret --tenant
4. Run:
   pac code push --environment https://.crm4.dynamics.com --solutionName

Expected behavior

The Code App is pushed successfully to the environment, same as when using a personal account.

Actual behavior

The command retries 4 times and fails with:
bolt.authentication.http.AuthenticatedClientException: Encountered internal server error.
at bolt.authentication.http.AuthenticatedHttpClient.Execute(...)
at bolt.authentication.http.AuthenticatedHttpClient.PutT
at bolt.module.code.PushVerb.SaveCodeApp(...) line 328
at bolt.module.code.PushVerb.SaveCodeApp(...) line 338
at bolt.module.code.PushVerb.ExecuteAsync(...) line 118

Correlation IDs

• b46d6575-7360-427c-bef3-61525ed25024
• 784ec08e-d1fb-4e35-9ffa-d6e3377ef8d5
• 635ebb3e-6fea-4db5-a8e0-42ba76ddd870
• 657926aa-46ec-4378-bf4e-42afb8668741

Additional context

• The service principal is correctly registered as a Management Application at tenant level.
• The service principal has an Application User with System Administrator role in the target environment.
• Authentication succeeds (pac auth who returns the correct organization and environment details).
• The error only occurs at the SaveCodeApp (PUT) step.
• The same pac code push command works correctly when authenticated with a personal user account.
• This blocks CI/CD automation for Code Apps using service principals.