[Jan Egil Ring (janegilring)]

This pull request updates documentation in the Azure Sovereign Cloud training materials to clarify the distinction between "deny" and "modify" policy effects, and to provide a detailed account of participant policy-permission validation during live testing. The changes improve guidance for policy assignment, remediation, and permissions required for remediation tasks.

Documentation and Guidance Improvements:

• Added a detailed section describing a live participant test, including the steps taken to validate policy permissions, remediation, and the removal of test resources, as well as clarifying the limitations of certain policy assignments (03-Azure/01-03-Infrastructure/01_Sovereign_Cloud/resources/tests/readme.md).
• Clarified in the walkthrough that the "Require a tag and its value" policy uses the deny effect, not modify, and explained that remediation and managed identity are not available for this assignment; pointed users to Task 10 for remediation of existing resources (03-Azure/01-03-Infrastructure/01_Sovereign_Cloud/walkthrough/challenge-01/solution-01.md).

Remediation and Permissions Clarifications:

• Added guidance on troubleshooting unavailable remediation options, emphasizing that policies with the deny effect (such as Task 3) cannot be remediated, and providing steps to ensure managed identity and Contributor role are correctly assigned for modify policies; also clarified the distinction between Resource Policy Contributor and Owner roles for granting access (03-Azure/01-03-Infrastructure/01_Sovereign_Cloud/walkthrough/challenge-01/solution-01.md).