refactor(srp): add renderer backend registry seam

tests/scripting/test_mono_script_runtime.cpp

@@ -45,6 +45,8 @@
 #include <XCEngine/Scripting/ScriptComponent.h>
 #include <XCEngine/Scripting/ScriptEngine.h>
 
+#include "Rendering/Internal/RenderPipelineFactory.h"
+
 #include <algorithm>
 #include <array>
 #include <cstdint>
@@ -75,6 +77,40 @@ void ExpectVector4Near(const XCEngine::Math::Vector4& actual, const XCEngine::Ma
     EXPECT_NEAR(actual.w, expected.w, tolerance);
 }
 
+std::shared_ptr<const XCEngine::Rendering::RenderPipelineAsset>
+CreateBuiltinForwardPipelineRendererAssetForTest() {
+    return std::make_shared<
+        XCEngine::Rendering::Pipelines::BuiltinForwardPipelineAsset>();
+}
+
+class ScopedPipelineRendererAssetFactoryRegistration final {
+public:
+    ScopedPipelineRendererAssetFactoryRegistration(
+        std::string key,
+        XCEngine::Rendering::Internal::PipelineRendererAssetFactory factory)
+        : m_key(std::move(key))
+        , m_registered(
+              XCEngine::Rendering::Internal::RegisterPipelineRendererAssetFactory(
+                  m_key,
+                  std::move(factory))) {
+    }
+
+    ~ScopedPipelineRendererAssetFactoryRegistration() {
+        if (m_registered) {
+            (void)XCEngine::Rendering::Internal::
+                UnregisterPipelineRendererAssetFactory(m_key);
+        }
+    }
+
+    bool IsRegistered() const {
+        return m_registered;
+    }
+
+private:
+    std::string m_key;
+    bool m_registered = false;
+};
+
 class CapturingLogSink final : public XCEngine::Debug::ILogSink {
 public:
     void Log(const XCEngine::Debug::LogEntry& entry) override {
@@ -2950,6 +2986,42 @@ TEST_F(
         nullptr);
 }
 
+TEST_F(
+    MonoScriptRuntimeTest,
+    ManagedRenderPipelineBridgeResolvesRegisteredAliasBackendKey) {
+    ScopedPipelineRendererAssetFactoryRegistration registration(
+        "BuiltinForwardAlias",
+        &CreateBuiltinForwardPipelineRendererAssetForTest);
+    ASSERT_TRUE(registration.IsRegistered());
+
+    const auto bridge =
+        XCEngine::Rendering::Pipelines::GetManagedRenderPipelineBridge();
+    ASSERT_NE(bridge, nullptr);
+
+    const XCEngine::Rendering::Pipelines::ManagedRenderPipelineAssetDescriptor
+        descriptor = {
+            "GameScripts",
+            "Gameplay",
+            "ManagedBuiltinForwardAliasRenderPipelineProbeAsset"
+        };
+
+    std::shared_ptr<const XCEngine::Rendering::Pipelines::ManagedRenderPipelineAssetRuntime>
+        assetRuntime = bridge->CreateAssetRuntime(descriptor);
+    ASSERT_NE(assetRuntime, nullptr);
+
+    const std::shared_ptr<const XCEngine::Rendering::RenderPipelineAsset>
+        rendererAsset = assetRuntime->GetPipelineRendererAsset();
+    ASSERT_NE(rendererAsset, nullptr);
+
+    std::unique_ptr<XCEngine::Rendering::RenderPipeline> pipeline =
+        rendererAsset->CreatePipeline();
+    ASSERT_NE(pipeline, nullptr);
+    EXPECT_NE(
+        dynamic_cast<XCEngine::Rendering::Pipelines::BuiltinForwardPipeline*>(
+            pipeline.get()),
+        nullptr);
+}
+
 TEST_F(
     MonoScriptRuntimeTest,
     ManagedRenderPipelineBridgeUsesDefaultRendererSelectionForNativeBackendAsset) {