Fixes working directory handling

Ensures build and cleanup processes run from the expected project location.

Prevents temporary state files from being created or removed in the wrong folder, which avoids stale markers and cleanup failures when launched from the UI or another directory.

FFUDevelopment/BuildFFUVM.ps1

@@ -5692,7 +5692,8 @@ If (Test-Path -Path "$FFUDevelopmentPath\dirty.txt") {
     Get-FFUEnvironment
 }
 WriteLog 'Creating dirty.txt file'
-New-Item -Path .\ -Name "dirty.txt" -ItemType "file" | Out-Null
+$dirtyFilePath = Join-Path -Path $FFUDevelopmentPath -ChildPath 'dirty.txt'
+New-Item -Path $dirtyFilePath -ItemType "file" | Out-Null
 
 # Early CLI prompt for additional FFUs (only if enabled and not provided)
 if ($BuildUSBDrive -and $CopyAdditionalFFUFiles -and ((-not $AdditionalFFUFiles) -or ($AdditionalFFUFiles.Count -eq 0))) {
@@ -7615,7 +7616,8 @@ else {
 }
 
 #Clean up dirty.txt file
-Remove-Item -Path .\dirty.txt -Force | out-null
+$dirtyFilePath = Join-Path -Path $FFUDevelopmentPath -ChildPath 'dirty.txt'
+Remove-Item -Path $dirtyFilePath -Force | out-null
 # Remove per-run session folder if present
 $sessionDir = Join-Path $FFUDevelopmentPath '.session'
 if (Test-Path -Path $sessionDir) {