Synchronize the client and select installed language packs (#3)

The launcher synchronizes the current native client, retains manifest-listed ruRU archives and launches the game with WOW_LOCALE=auto. Includes the prepared cleanup of obsolete Extentions directories in both client roots while preserving manifest-required files and unrelated user state.

Version: 1.0.7+10. Deployment now judges native OpenSSL commands by their exit codes while retaining key and signature verification.

Verified on Windows through FVM: full format/analyze, all 76 tests, production dry run, x64 runtime imports and DSA installer signature. The original dirty checkout was preserved. Publication follows the localized client release.

tool/deploy_launcher.ps1

@@ -94,9 +94,19 @@ function Invoke-RequiredCommand {
         [Parameter(Mandatory = $true)][string[]]$Arguments
     )
 
-    & $Command @Arguments
-    if ($LASTEXITCODE -ne 0) {
-        throw "Command failed with exit code ${LASTEXITCODE}: $Command"
+    # Windows PowerShell represents native stderr as error records even on exit 0.
+    # OpenSSL writes its normal key-reading notices there; the exit code is the verdict.
+    $previousPreference = $ErrorActionPreference
+    try {
+        $ErrorActionPreference = 'Continue'
+        & $Command @Arguments
+        $commandExitCode = $LASTEXITCODE
+    }
+    finally {
+        $ErrorActionPreference = $previousPreference
+    }
+    if ($commandExitCode -ne 0) {
+        throw "Command failed with exit code ${commandExitCode}: $Command"
     }
 }
 
@@ -559,12 +569,9 @@ try {
     $previousPath = $env:PATH
     try {
         $env:PATH = "$gitOpenSslDirectory;$env:PATH"
-        $signOutput = & $dart run auto_updater:sign_update `
-            $installerPath `
-            $privateKey 2>&1
-        if ($LASTEXITCODE -ne 0) {
-            throw "Could not sign the installer: $signOutput"
-        }
+        $signOutput = Invoke-RequiredCommand -Command $dart -Arguments @(
+            'run', 'auto_updater:sign_update', $installerPath, $privateKey
+        ) 2>&1
     }
     finally {
         $env:PATH = $previousPath