fix(tests): 🐛 Update JSON test script and fix path handling

* Added a TODO comment for clarity in `JsonTest.Tests.ps1`.
* Modified path handling in `PlasterManifestValidation.Tests.ps1` to ensure compatibility across platforms.

Author: HeyItsGilbert

tests/JsonTest.Tests.ps1

@@ -1,3 +1,4 @@
+# TODO: What is this? GS
 # Phase 2 Test: JSON Template Creation and Execution
 
 Write-Host "=== Plaster 2.0 Phase 2 - JSON Template Test ===" -ForegroundColor Cyan

tests/PlasterManifestValidation.Tests.ps1

@@ -221,7 +221,7 @@ Describe 'Module Error Handling Tests' {
 
     Context 'Template cannot write outside of the user-specified DestinationPath' {
         It 'Throws on modify path that is absolute path' {
-
+            $root = if ($IsWindows) { $env:LOCALAPPDATA } else { '/' }
             @"
 <?xml version="1.0" encoding="utf-8"?>
 <plasterManifest schemaVersion="0.3" xmlns="http://www.microsoft.com/schemas/PowerShell/Plaster/v1">
@@ -243,7 +243,7 @@ Describe 'Module Error Handling Tests' {
         </modify>
     </content>
 </plasterManifest>
-"@ | Out-File $PlasterManifestPath -Encoding utf8
+"@ -f $root | Out-File $PlasterManifestPath -Encoding utf8
 
             { Invoke-Plaster -TemplatePath $TemplateDir -DestinationPath $OutDir -NoLogo 6> $null } | Should -Throw
         }