iOS: bootstrap Vulkan via main-binary dlsym (vkGetInstanceProcAddr re-exported)

sources/engine/Stride.Graphics/Vulkan/GraphicsAdapterFactory.Vulkan.cs

@@ -28,13 +28,12 @@ namespace Stride.Graphics
             // when one is installed (e.g. via 'brew install vulkan-loader') because only the loader
             // chains validation layers — bundled MoltenVK alone is an ICD and ignores VK_LAYER_*.
             // If no loader is available, fall back to the bundled MoltenVK at runtimes/<rid>/native/.
-            // On iOS, MoltenVK is statically linked into the app bundle (iOS forbids dlopen of
-            // arbitrary dylibs); "__Internal" resolves to the main executable's symbol table,
-            // so Vortice's NativeLibrary.GetExport finds vkGetInstanceProcAddr there.
+            // On iOS, MoltenVK is statically linked into the app binary: dlopen the executable itself,
+            // which exports vkGetInstanceProcAddr (see Stride.Core.NativeLibraries.targets).
             string vkLibraryName = Platform.Type switch
             {
                 PlatformType.macOS => ResolveMacOSVulkanLibrary(),
-                PlatformType.iOS => "__Internal",
+                PlatformType.iOS => Environment.ProcessPath,
                 _ => null,
             };
             var result = vkInitialize(vkLibraryName);

sources/sdk/Stride.Build.Sdk/Sdk/Stride.Dependencies.targets

@@ -17,7 +17,9 @@
     Platform-specific handling:
     - Desktop (Windows/Linux/macOS): Native libs copied as None items
     - Android: Native libs added as AndroidNativeLibrary
-    - iOS: Native libs linked via mtouch arguments
+    - iOS: Native libs added as NativeReference (Kind=Static, ForceLoad=True) so libfoo.a is
+      whole-archive linked into the main executable; libMoltenVK.a additionally re-exports
+      vkGetInstanceProcAddr so Vortice.Vulkan's dlsym-based loader finds it.
     ================================================================
   -->
 
@@ -197,6 +199,14 @@
         <ForceLoad>True</ForceLoad>
         <SmartLink>False</SmartLink>
       </NativeReference>
+      <!-- libMoltenVK.a: re-export vkGetInstanceProcAddr from the final binary's dynamic
+           symbol table. Vortice.Vulkan bootstraps with NativeLibrary.Load("__Internal") +
+           NativeLibrary.GetExport(handle, "vkGetInstanceProcAddr") → dlsym, which only sees
+           dynamically-exported symbols. Static-linked .a symbols are local by default ("t" in
+           nm), so without this flag Vortice's vkInitialize returns ErrorInitializationFailed. -->
+      <NativeReference Update="@(NativeReference)"
+          Condition="$([System.String]::new('%(Identity)').EndsWith('libMoltenVK.a'))"
+          LinkerFlags="-Wl,-exported_symbol,_vkGetInstanceProcAddr" />
     </ItemGroup>
   </Target>