Clarify networking requirements for multi-region Power Platform geographies

[mattdot]

This pull request improves the documentation for infrastructure resilience, testing, and advanced deployment scenarios. It refactors and expands the disaster recovery and resilience guidance, moves detailed testing instructions to a dedicated guide, and clarifies networking requirements for multi-region Power Platform geographies. The changes are primarily documentation updates to help users better understand deployment options, security, and operational considerations.

Documentation Restructuring and Content Relocation:

• The detailed testing instructions have been removed from README.md and replaced with a concise pointer to a new Testing Guide, streamlining the main documentation and making test execution guidance easier to find and maintain.

Infrastructure Resilience and Disaster Recovery Guidance:

• The former docs/bcdr_considerations.md has been renamed to docs/infrastructure_resilience.md and significantly rewritten. The new guide clearly defines three deployment tiers (Basic, Zone-redundant, Regional failover ready), provides prescriptive recommendations for each, and clarifies that the template provides only the foundational networking and identity scaffolding for regional failover, not full automation.
• The guide now includes explicit guidance about dual-region virtual network requirements for multi-region Power Platform geographies, ensuring users do not remove necessary networking scaffolding in those scenarios. [1] [2]

Clarifications and Known Limitations:

• The documentation now explicitly states that the template does not automate cross-region failover, data replication, or DNS/traffic management for regional disaster recovery; these must be handled manually by the user. [1] [2]
• Known issues and workarounds regarding the inability to disable secondary-region networking scaffolding in development scenarios are documented, helping users understand current template limitations and cost implications.

Additional Improvements:

• References to supporting guides (security, CI/CD, custom networking, custom resource groups) have been updated for clarity and consistency, with corrected links and improved explanations of advanced scenarios.
• The last updated date has been refreshed to reflect the new guidance.

Resolves #304

[Copilot]

Pull Request Overview

Clarifies mandatory dual-region networking requirements in multi-region Power Platform geographies and updates disaster recovery documentation to remove prior guidance about disabling secondary-region networking. Emphasizes that dual virtual networks are a compliance prerequisite and adds authoritative reference links.

• Clarifies that dual-region networking is mandatory (cannot be disabled) in multi-region geographies.
• Replaces prior workaround/limitation section with forward-looking status note.
• Adds important notice about lack of automated cross-region failover plus new reference links.

[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 7 comments.