Fix: remove stale maccatalyst CLI workaround, use SDK 0.1.26 native fix

SDK 0.1.26 (PR github/copilot-sdk#485) now natively maps maccatalyst
RIDs to osx RIDs for CLI download. Our _FixCopilotRidForMacCatalyst
workaround's condition ('$(_CopilotPlatform)' == '') no longer fires
since the SDK sets it first, causing _CopilotOriginalRid to never be
set, which skipped both the maccatalyst-arm64 runtime copy AND the
MonoBundle copy. Clean builds would produce an app with no copilot CLI.

Changes:
- Remove _FixCopilotRidForMacCatalyst (SDK handles this now)
- Update _CopyCopilotCliForMacCatalyst to detect maccatalyst via
  GetTargetPlatformIdentifier instead of _CopilotOriginalRid
- Update _IncludeCopilotCliInBundle with same condition fix
- Use $(RuntimeIdentifier) directly for the maccatalyst output path

Fixes: github/copilot-sdk#454

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: PureWeen

PolyPilot/PolyPilot.csproj

@@ -87,29 +87,16 @@
         <TrimmerRootAssembly Include="GitHub.Copilot.SDK" RootMode="All" />
     </ItemGroup>
 
-    <!-- The SDK only maps standard RIDs (osx-arm64, etc.) to download the copilot CLI.
-         Mac Catalyst uses maccatalyst-arm64 which the SDK doesn't recognize, so the
-         download is silently skipped. Map it to the darwin-arm64 npm package. -->
-    <Target Name="_FixCopilotRidForMacCatalyst" BeforeTargets="_DownloadCopilotCli">
-        <PropertyGroup Condition="'$(_CopilotPlatform)' == '' And $(_CopilotRid.StartsWith('maccatalyst-arm64'))">
-            <_CopilotPlatform>darwin-arm64</_CopilotPlatform>
-            <_CopilotBinary>copilot</_CopilotBinary>
-            <_CopilotOriginalRid>$(_CopilotRid)</_CopilotOriginalRid>
-            <_CopilotRid>osx-arm64</_CopilotRid>
-        </PropertyGroup>
-        <PropertyGroup Condition="'$(_CopilotPlatform)' == '' And '$(_CopilotRid)' == 'maccatalyst-x64'">
-            <_CopilotPlatform>darwin-x64</_CopilotPlatform>
-            <_CopilotBinary>copilot</_CopilotBinary>
-            <_CopilotOriginalRid>$(_CopilotRid)</_CopilotOriginalRid>
-            <_CopilotRid>osx-x64</_CopilotRid>
-        </PropertyGroup>
-    </Target>
-
-    <!-- The SDK at runtime uses RuntimeInformation.RuntimeIdentifier (maccatalyst-arm64)
-         to locate the binary, so also copy it to that path. -->
-    <Target Name="_CopyCopilotCliForMacCatalyst" AfterTargets="_CopyCopilotCliToOutput" Condition="'$(_CopilotOriginalRid)' != ''">
+    <!-- SDK 0.1.26+ natively maps maccatalyst RIDs for CLI download (issue #454).
+         The _FixCopilotRidForMacCatalyst workaround is no longer needed. -->
+
+    <!-- The SDK (0.1.26+) now maps maccatalyst RIDs to osx RIDs for download.
+         However, at runtime RuntimeInformation.RuntimeIdentifier returns maccatalyst-arm64,
+         so the SDK looks for runtimes/maccatalyst-arm64/native/copilot. We still need to
+         copy the binary to that path AND into the .app bundle's MonoBundle. -->
+    <Target Name="_CopyCopilotCliForMacCatalyst" AfterTargets="_CopyCopilotCliToOutput" Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'maccatalyst' And '$(_CopilotPlatform)' != ''">
         <PropertyGroup>
-            <_CopilotMacCatalystOutputDir>$(OutDir)runtimes/$(_CopilotOriginalRid)/native</_CopilotMacCatalystOutputDir>
+            <_CopilotMacCatalystOutputDir>$(OutDir)runtimes/$(RuntimeIdentifier)/native</_CopilotMacCatalystOutputDir>
             <_CopilotCacheDir>$(IntermediateOutputPath)copilot-cli/$(CopilotCliVersion)/$(_CopilotPlatform)</_CopilotCacheDir>
         </PropertyGroup>
         <MakeDir Directories="$(_CopilotMacCatalystOutputDir)" />
@@ -142,7 +129,7 @@
     <!-- Ensure the copilot CLI binary is included in the Mac Catalyst .app bundle.
          MAUI flattens everything into MonoBundle, so runtimes/ paths don't work.
          Copy the binary directly into the .app bundle's MonoBundle. -->
-    <Target Name="_IncludeCopilotCliInBundle" AfterTargets="Build" Condition="'$(_CopilotOriginalRid)' != ''">
+    <Target Name="_IncludeCopilotCliInBundle" AfterTargets="Build" Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'maccatalyst' And '$(_CopilotPlatform)' != ''">
         <PropertyGroup>
             <_CopilotCacheDir>$(IntermediateOutputPath)copilot-cli/$(CopilotCliVersion)/$(_CopilotPlatform)</_CopilotCacheDir>
             <_AppBundleMonoBundle>$(OutDir)PolyPilot.app/Contents/MonoBundle</_AppBundleMonoBundle>