fix(ci): make launcher space guidance culture invariant

src/AcDream.Launcher.Core/Installation/LauncherInstaller.cs

@@ -1,6 +1,7 @@
 using AcDream.Launcher.Core.Integrity;
 using AcDream.Launcher.Core.Launching;
 using AcDream.Platform;
+using System.Globalization;
 
 namespace AcDream.Launcher.Core.Installation;
 
@@ -326,9 +327,9 @@ public sealed class LauncherInstaller : ILauncherInstaller
         {
             string message =
                 $"The optimized world-data rebuild needs at least "
-                + $"{FullRebuildRequiredFreeBytes / (1024d * 1024d * 1024d):N1} GiB free "
+                + $"{FormatGiB(FullRebuildRequiredFreeBytes)} GiB free "
                 + $"beside the active package; only "
-                + $"{availableBytes / (1024d * 1024d * 1024d):N1} GiB is available.";
+                + $"{FormatGiB(availableBytes)} GiB is available.";
             Report(progress, LauncherInstallPhase.Failed, message);
             throw new LauncherInstallException(message);
         }
@@ -636,6 +637,9 @@ public sealed class LauncherInstaller : ILauncherInstaller
             .ConfigureAwait(false);
     }
 
+    private static string FormatGiB(long bytes) =>
+        (bytes / (1024d * 1024d * 1024d)).ToString("N1", CultureInfo.InvariantCulture);
+
     public async Task<LauncherInstallResult> ApplyContentUpdateAsync(
         string datDirectory,
         int threads,

tests/AcDream.Launcher.Core.Tests/Installation/LauncherInstallerTests.cs

@@ -1,4 +1,5 @@
 using System.Diagnostics;
+using System.Globalization;
 using System.Text.Json.Nodes;
 using AcDream.Launcher.Core.Integrity;
 using AcDream.Launcher.Core.Installation;
@@ -149,6 +150,10 @@ public sealed class LauncherInstallerTests : IDisposable
 
     [Fact]
     public async Task InsufficientFreeSpaceStopsBeforeBakeAndReportsExactRequirement()
+    {
+        CultureInfo originalCulture = CultureInfo.CurrentCulture;
+        CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo("sv-SE");
+        try
         {
             bool childStarted = false;
             var runner = new FakeBakeProcessRunner((_, _, _) =>
@@ -173,6 +178,11 @@ public sealed class LauncherInstallerTests : IDisposable
                 LauncherInstaller.GetFullRebuildCandidatePath(
                     Path.Combine(_paths.DataDirectory, "pak", "acdream.pak"))));
         }
+        finally
+        {
+            CultureInfo.CurrentCulture = originalCulture;
+        }
+    }
 
     [Fact]
     public async Task FullContentMigrationPersistsClientGateAcrossLauncherRestart()