feat: script refinement — Azure Local conversion path (01–05 scripts)

[kristopherjturner]

Overview

Refine and harden the Azure Local conversion path scripts (scripts/azurelocal/) that convert Arc-enrolled Gen1 VMs to Gen2. Each script in the 01–05 sequence should follow consistent patterns for pre-flight validation, execution, and logging.

Scope

• 01-PreflightCheck.ps1 — OS detection, disk layout validation, Arc enrollment state check
• 02-ConvertDisk.ps1 — MBR → GPT conversion with safeguards (BCD backup, partition table validation)
• 03-ConvertVM.ps1 — Gen1 → Gen2 firmware swap with Secure Boot and vTPM configuration
• 04-PostConversionValidation.ps1 — Boot confirmation, Arc state verification, workload health check
• 05-Rollback.ps1 — Staged rollback capability (each converted step reversible)
• Consistent parameter sets, verbose logging, and structured output across all scripts

Acceptance Criteria

• All 5 scripts follow consistent parameter + output contract
• Pre-flight check catches all known incompatible configurations before any changes
• Rollback script can restore to pre-conversion state at any conversion stage
• Arc enrollment state preserved and confirmed post-conversion
• Pester tests for each script (covered in feat: script refinement — Hyper-V standalone conversion path #7)

Dependencies

• Parent Epic: [Epic] VM Conversion Toolkit Full Build-Out #5
• Toolkit variable registry: Create master variables registry to standardize variables across all repos azurelocal-toolkit#4