fix: PS 5.1 compatibility, encoding cleanup, GPU detection, and test fixes

- Fixed PS 7+ conditional assignment syntax across Common.ps1, simplify11.ps1, and UniGetUI.ps1 for PS 5.1 compatibility
- Fixed version.json path from root to config/version.json in simplify11.ps1
- Replaced em-dash characters with ASCII hyphens in Common.ps1, Tweaks.Universal.ps1, and ExternalLauncher.ps1
- Fixed trailing whitespace in Organizer.ps1
- Fixed Join-Path calls with 3+ arguments in test files for PS 5.1 two-argument limit
- Fixed Invoke-SecureScript test to expect throw on hash mismatch
- Added missing Mock Confirm-ExternalTool in Invoke-Tool tests
- Fixed Invoke-HybridTweaks to check return values and report when GPUs are not detected
- Added NVIDIA GPU detection via display adapter registry scan before applying tweaks
- Changed Invoke-NvidiaTweaks and Invoke-AMDTweaks to return boolean success indicators

Author: emylfy

CHANGELOG.md

@@ -7,6 +7,19 @@ and this project uses [Calendar Versioning](https://calver.org/) (YY.M format).
 
 ## [26.3] - 2026-03-21
 
+### March 21 — PowerShell 5.1 compatibility, test fixes, encoding cleanup
+
+- Fixed all PS 7+ `$var = if () {} else {}` assignment syntax across `Common.ps1` (4 instances), `simplify11.ps1`, `UniGetUI.ps1` for PS 5.1 compatibility
+- Fixed `simplify11.ps1` version.json path from root to `config/version.json` (was always showing "unknown")
+- Fixed em-dash (U+2014) characters in `Common.ps1`, `Tweaks.Universal.ps1`, `ExternalLauncher.ps1` replaced with ASCII hyphen to resolve `PSUseBOMForUnicodeEncodedFile` warnings and PS 5.1 parse failures on files without BOM
+- Fixed trailing whitespace in `Organizer.ps1`
+- Fixed `Join-Path` calls with 3+ arguments in `Common.Tests.ps1`, `Common.Utilities.Tests.ps1`, `Config.Tests.ps1`, `ExternalLauncher.Tests.ps1` for PS 5.1 (only supports 2-argument `Join-Path`)
+- Fixed `Invoke-SecureScript` test to match actual `throw` behavior on hash mismatch
+- Fixed `Invoke-Tool` tests with missing `Mock Confirm-ExternalTool` to prevent null reference from unmocked `Read-Host`
+- Fixed `Invoke-HybridTweaks` in `Tweaks.GPU.ps1` — no longer reports success when a GPU is not detected; now checks return values from both `Invoke-NvidiaTweaks` and `Invoke-AMDTweaks`
+- Added NVIDIA GPU detection to `Invoke-NvidiaTweaks` — scans display adapter registry before applying tweaks, skips with WARNING if not found
+- Changed `Invoke-NvidiaTweaks` and `Invoke-AMDTweaks` to return `$true`/`$false` indicating whether tweaks were applied
+
 ### March 21 — Power Management split, driver improvements, security hardening, docs overhaul
 
 - Added `Tweaks.Power.ps1` — aggressive power tweaks extracted into separate module with AC power warning

modules/system/Tweaks.GPU.ps1

@@ -16,9 +16,18 @@ function Show-GPUMenu {
 
 function Invoke-HybridTweaks {
     Write-Log -Message "Applying tweaks for hybrid GPU configuration (NVIDIA + AMD)..." -Level INFO
-    Invoke-NvidiaTweaks -NoExit
-    Invoke-AMDTweaks -NoExit
-    Write-Log -Message "Successfully applied tweaks for both NVIDIA and AMD GPUs." -Level SUCCESS
+    $nvidiaOk = Invoke-NvidiaTweaks -NoExit
+    $amdOk = Invoke-AMDTweaks -NoExit
+
+    if ($nvidiaOk -and $amdOk) {
+        Write-Log -Message "Successfully applied tweaks for both NVIDIA and AMD GPUs." -Level SUCCESS
+    } elseif ($nvidiaOk) {
+        Write-Log -Message "Applied NVIDIA tweaks. AMD GPU was not detected." -Level WARNING
+    } elseif ($amdOk) {
+        Write-Log -Message "Applied AMD tweaks. NVIDIA GPU was not detected." -Level WARNING
+    } else {
+        Write-Log -Message "No supported GPUs detected." -Level ERROR
+    }
     Write-Host ""
     Write-Host "$Purple Press any key to return to the GPU menu...$Reset"
     $null = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
@@ -30,6 +39,28 @@ function Invoke-NvidiaTweaks {
     )
 
     # source - https://github.com/AlchemyTweaks/Verified-Tweaks/blob/main/Nvidia/RmGpsPsEnablePerCpuCoreDpc
+    # Detect NVIDIA GPU presence
+    $nvidiaFound = $false
+    $classPath = "HKLM:\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}"
+    foreach ($idx in @("0000", "0001", "0002", "0003")) {
+        $devPath = "$classPath\$idx"
+        if (Test-Path $devPath) {
+            $provider = (Get-ItemProperty -Path $devPath -Name "ProviderName" -ErrorAction SilentlyContinue).ProviderName
+            if ($provider -match "NVIDIA") {
+                $nvidiaFound = $true
+                break
+            }
+        }
+    }
+    if (-not $nvidiaFound) {
+        Write-Log -Message "No NVIDIA GPU found in display adapter registry. Skipping NVIDIA tweaks." -Level WARNING
+        if (-not $NoExit) {
+            Write-Host "`n$Purple Press any key to return to the GPU menu...$Reset"
+            $null = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
+        }
+        return $false
+    }
+
     Set-RegistryValue -Path "HKLM:\SYSTEM\CurrentControlSet\Control\GraphicsDrivers" -Name "RmGpsPsEnablePerCpuCoreDpc" -Type "DWord" -Value "1" -Message "Enabled per-CPU core DPC for NVIDIA drivers"
     Set-RegistryValue -Path "HKLM:\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Power" -Name "RmGpsPsEnablePerCpuCoreDpc" -Type "DWord" -Value "1" -Message "Enabled power-aware per-CPU core DPC"
     Set-RegistryValue -Path "HKLM:\SYSTEM\CurrentControlSet\Services\nvlddmkm" -Name "RmGpsPsEnablePerCpuCoreDpc" -Type "DWord" -Value "1" -Message "Enabled NVIDIA driver per-CPU core DPC"
@@ -41,6 +72,7 @@ function Invoke-NvidiaTweaks {
         Write-Host "$Purple Press any key to return to the GPU menu...$Reset"
         $null = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
     }
+    return $true
 }
 
 function Invoke-AMDTweaks {
@@ -69,7 +101,7 @@ function Invoke-AMDTweaks {
             Write-Host "`n$Purple Press any key to return to the GPU menu...$Reset"
             $null = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
         }
-        return
+        return $false
     }
     Write-Log -Message "Found AMD GPU at $amdPath" -Level INFO
     Set-RegistryValue -Path $amdPath -Name "AllowSnapshot" -Type "DWord" -Value "0" -Message "Disabled AMD snapshot feature"
@@ -108,4 +140,5 @@ function Invoke-AMDTweaks {
         Write-Host "$Purple Press any key to return to the GPU menu...$Reset"
         $null = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
     }
+    return $true
 }

modules/system/Tweaks.Universal.ps1

@@ -193,7 +193,7 @@ function Invoke-NetworkTweaks {
 
     # Disable network throttling - especially helpful with gigabit networks
     # source - https://youtu.be/EmdosMT5TtA
-    # 4294967295 = 0xFFFFFFFF (max DWORD) — effectively disables network throttling
+    # 4294967295 = 0xFFFFFFFF (max DWORD) - effectively disables network throttling
     Set-RegistryValue -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile" -Name "NetworkThrottlingIndex" -Type "DWord" -Value "4294967295" -Message "Disabled network throttling for maximum network performance"
     Set-RegistryValue -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile" -Name "NoLazyMode" -Type "DWord" -Value "1" -Message "Disabled lazy mode for network operations"
 }

modules/tools/ExternalLauncher.ps1

@@ -1,5 +1,5 @@
 # Config-driven external tool launcher
-# All tool definitions live in config/tools.json — no more per-tool wrapper files
+# All tool definitions live in config/tools.json - no more per-tool wrapper files
 
 param(
     [Parameter(Mandatory = $true)]

modules/unigetui/UniGetUI.ps1

@@ -80,12 +80,12 @@ function Show-AppCategoryMenu {
             default { continue }
         }
 
-        $scriptPath = if ($PSScriptRoot) {
-            $PSScriptRoot
+        if ($PSScriptRoot) {
+            $scriptPath = $PSScriptRoot
         } elseif ($MyInvocation.MyCommand.Path) {
-            Split-Path -Parent $MyInvocation.MyCommand.Path
+            $scriptPath = Split-Path -Parent $MyInvocation.MyCommand.Path
         } else {
-            $PWD.Path
+            $scriptPath = $PWD.Path
         }
 
         $projectRoot = Split-Path -Parent (Split-Path -Parent $scriptPath)