Release v0.3.0: move settings into an on-demand single-instance configurator

tests/update.ps1

@@ -30,6 +30,10 @@ try {
     }
     $source=Join-Path $root 'source'; [IO.Directory]::CreateDirectory($source) | Out-Null
     Copy-Item -LiteralPath $Executable -Destination (Join-Path $source 'KSwitcher.exe')
+    $configurator = Join-Path (Split-Path $Executable) 'KSwitcher.Config.exe'
+    if (Test-Path -LiteralPath $configurator) {
+        Copy-Item -LiteralPath $configurator -Destination (Join-Path $source 'KSwitcher.Config.exe')
+    }
     foreach ($name in @('LICENSE','json-LICENSE.txt','README.md')) { [IO.File]::WriteAllText((Join-Path $source $name),'fixture') }
     [IO.Directory]::CreateDirectory((Join-Path $source 'dictionaries')) | Out-Null
     [IO.File]::WriteAllText((Join-Path $source 'dictionaries/en.txt'),'new dictionary')
@@ -57,11 +61,15 @@ try {
     $changed=[Collections.Generic.List[string]]::new()
     Install-Files $stage $target $backup $changed
     Assert ((Get-FileHash -LiteralPath (Join-Path $target 'KSwitcher.exe')).Hash -eq (Get-FileHash -LiteralPath $Executable).Hash) 'replacement installed'
+    if (Test-Path -LiteralPath $configurator) {
+        Assert ((Get-FileHash -LiteralPath (Join-Path $target 'KSwitcher.Config.exe')).Hash -eq (Get-FileHash -LiteralPath $configurator).Hash) 'configurator installed'
+    }
     Assert ([IO.File]::ReadAllText((Join-Path $target 'data/settings.json')) -eq 'personal settings') 'settings preserved'
     Assert ([IO.File]::ReadAllText((Join-Path $target 'dictionaries/en.txt')) -eq 'personal dictionary') 'dictionary preserved'
     Undo-Files $target $backup $changed
     Assert ([IO.File]::ReadAllText((Join-Path $target 'KSwitcher.exe')) -eq 'old binary fixture') 'rollback restores original'
     Assert (!(Test-Path -LiteralPath (Join-Path $target 'README.md'))) 'rollback removes newly introduced files'
+    Assert (!(Test-Path -LiteralPath (Join-Path $target 'KSwitcher.Config.exe'))) 'rollback removes newly introduced configurator'
     # Fail after the original exe has moved to backup, as if the staged file vanished.
     $stage2=Join-Path $root 'stage2'; [IO.Directory]::CreateDirectory($stage2) | Out-Null
     [IO.File]::WriteAllText((Join-Path $stage2 'KSwitcher.exe'),'new binary fixture')