✨ Implement JFC drive mapping refactor with comprehensive test suite

[J-MaFf]

What does this PR do?

Implements the complete JFC drive mapping refactor by converting location-specific batch scripts into a unified PowerShell solution. This PR adds:

• Invoke-DriveMapping.ps1 — Consolidated script that detects machine site code and maps persistent network drives (U:, W:, S:) for all 30 JFC locations
• Invoke-DriveMapping.Tests.ps1 — Comprehensive Pester test suite with 54 tests covering all location configurations, special cases, and error scenarios
• Support for all 30 JFC locations with proper server mappings
• Special handling for terminal servers (TRM, ACT, ACP), IP-based servers (JOH, JPH), and shared server configurations
• Full verbose logging support for debugging drive mapping issues

Why are we doing this?

• Replaces ~30+ location-specific BAT scripts with a single, maintainable PowerShell script
• Improves debuggability — Verbose output makes troubleshooting network connectivity issues easier
• Modernizes approach — PowerShell provides better error handling and logging than batch scripts
• Facilitates future enhancements — Makes it easier to add KMSApp deployment, User.bat execution, and printer setup later
• All tests pass — 54 Pester tests validate the implementation across all location scenarios

How should this be tested?

1. Deploy script to test machines representing different JFC location codes (JFC, JOH, JPH, JBO, etc.)
2. Verify drives U:, W:, and S: (where applicable) connect to correct servers
3. Test verbose output with: .\Invoke-DriveMapping.ps1 -Verbose
4. Validate terminal server detection (TRM, ACT, ACP suffixes should skip mapping)
5. Test IP-based servers (JOH and JPH should map to IP addresses, not DNS names)
6. Verify drive persistence across logoffs

Any deployment notes?

• Script retains backward compatibility with batch scripts (can run in parallel during transition)
• BAT scripts should remain in place as backup during initial deployment
• Script can be called from PowerShell GPO scripts or batch wrapper scripts
• Execution policy may need to be configured in Group Policy for production deployment
• All 30 location configurations have been tested and validated

Closes #84