refactor(srp): unify engine managed assembly discovery

engine/include/XCEngine/Scripting/Mono/MonoScriptRuntime.h

@@ -54,6 +54,14 @@ public:
     explicit MonoScriptRuntime(Settings settings = {});
     ~MonoScriptRuntime() override;
 
+    static constexpr const char* EngineAssemblyManifestFileName =
+        "XCEngine.EngineAssemblies.txt";
+    static std::filesystem::path GetEngineAssemblyManifestPath(
+        const std::filesystem::path& assemblyDirectory);
+    static bool DiscoverEngineAssemblies(
+        Settings& ioSettings,
+        std::string* outError = nullptr);
+
     bool Initialize();
     void Shutdown();
 
@@ -190,7 +198,7 @@ private:
         MonoImage* image = nullptr;
     };
 
-    void ResolveSettings();
+    bool ResolveSettings();
     bool InitializeRootDomain();
     bool CreateAppDomain();
     void DestroyAppDomain();