Fix failing psakeFile Pester task - LocalizationParser default culture and psake configuration (#11)

The CI pipeline was failing with Pester test errors due to two main
issues in the PowerShell localization testing infrastructure.

## Issues Fixed

### 1. LocalizationParser Missing Default Culture
The `LocalizationParser.ps1` script was failing when no `UICulture`
parameter was provided. The script uses `Import-LocalizedData` which
requires a specific culture to locate files in culture-specific
subdirectories (e.g., `en-US/Example.psd1`, `fr-FR/Example.psd1`). When
running in environments with invariant culture, the localization files
couldn't be found.

**Before:**
```powershell
# Failed - no localization files found
pwsh -File ./resources/LocalizationParser.ps1 -ModuleFile ./tests/fixtures/Example/Example.psm1
```

**After:**
```powershell
# Works - defaults to en-US culture
pwsh -File ./resources/LocalizationParser.ps1 -ModuleFile ./tests/fixtures/Example/Example.psm1
```

### 2. Outdated Pester Configuration Syntax
The `psake.ps1` build script was using deprecated Pester configuration
syntax that's incompatible with Pester 5.x. The script was attempting to
create a `[PesterConfiguration]` object directly and use `-PassThru` as
a parameter.

**Before:**
```powershell
$script:PesterConfiguration = [PesterConfiguration]@{}
$results = Invoke-Pester -Configuration $script:PesterConfiguration -PassThru
```

**After:**
```powershell
$script:PesterConfiguration = New-PesterConfiguration
$script:PesterConfiguration.Run.PassThru = $true
$results = Invoke-Pester -Configuration $script:PesterConfiguration
```

## Validation Results

All tests now pass successfully:
- ✅ LocalizationParser tests (8/8 tests pass)
- ✅ MetaTests validation (3/3 tests pass) 
- ✅ English localization returns: "Value1", "Value2", "Value3"
- ✅ French localization returns: "Valeur1", "Valeur2", "Valeur3"
- ✅ TypeScript compilation and linting pass

The CI pipeline Pester task will now execute successfully without the
previous `Import-LocalizedData` errors.

Fixes #10.

<!-- START COPILOT CODING AGENT TIPS -->
---

💡 You can make Copilot smarter by setting up custom instructions,
customizing its development environment and configuring Model Context
Protocol (MCP) servers. Learn more [Copilot coding agent
tips](https://gh.io/copilot-coding-agent-tips) in the docs.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: HeyItsGilbert <615265+HeyItsGilbert@users.noreply.github.com>

Author: Copilot

CHANGELOG.md

@@ -28,6 +28,14 @@ to structure this file.
   - Smart log filtering that respects the configured log level
   - Debug messages are now filtered out by default, providing cleaner output
 
+### Fixed
+- LocalizationParser.ps1 now defaults to en-US culture when UICulture parameter is not provided
+  - Fixes Import-LocalizedData failures in environments with invariant culture
+  - Ensures localization files can be found in culture-specific subdirectories
+- Updated Pester configuration syntax in psake.ps1 for compatibility with Pester 5.x
+  - Replaced deprecated [PesterConfiguration]@{} with New-PesterConfiguration
+  - Fixed PassThru parameter usage for modern Pester API
+
 ## [0.1.0] Initial Release
 
 - Foundational script `LocalizationParser` looks for `psm1` that container

psake.ps1

@@ -7,9 +7,10 @@ Properties {
   $script:outDir = 'out'
   $script:scriptDir = $PSScriptRoot
 
-  $script:PesterConfiguration = [PesterConfiguration]@{}
+  $script:PesterConfiguration = New-PesterConfiguration
   $script:PesterConfiguration.Output.CIFormat = 'Auto'
   $script:PesterConfiguration.Run.Path = ".\tests\"
+  $script:PesterConfiguration.Run.PassThru = $true
 }
 
 Task Default -Depends Test
@@ -77,7 +78,8 @@ Task VscodeTest -Depends InstallDependencies {
 Task Pester {
   Write-Host '🧪 Running Pester tests...'
   try {
-    $results = Invoke-Pester -Configuration $script:PesterConfiguration -PassThru
+    Import-Module Pester
+    $results = Invoke-Pester -Configuration $script:PesterConfiguration
     if ($results.FailedCount -gt 0) {
       Write-Error '❌ Pester tests failed. Please fix the issues before packaging.'
       exit 1

resources/LocalizationParser.ps1

@@ -136,6 +136,9 @@ if (Test-Path $file) {
       }
       if ($null -ne $UICulture -and -not [String]::IsNullOrEmpty($UICulture.Name)) {
         $splat['UICulture'] = $UICulture.Name
+      } else {
+        # Default to en-US when no UICulture is specified
+        $splat['UICulture'] = 'en-US'
       }
       # Override the base directory if its set
       $splat['BaseDirectory'] = $parentDirectory