docs: update TEST_SPEC.md and README.md to reflect new directory structure

- TEST_SPEC.md: Updated test directory structure to reflect Core/Asset,
  Core/IO, and Resources/<Type> subdirectories
- TEST_SPEC.md: Updated module names and test counts (852 total)
- TEST_SPEC.md: Updated build commands for new Resources subdirectories
- README.md: Updated engine structure with Core/Asset/ and Core/IO/
- README.md: Updated Resources section with layered architecture
- README.md: Updated test coverage table with accurate counts

engine/include/XCEngine/Platform/IDynamicLibrary.h

@@ -0,0 +1,24 @@
+#pragma once
+
+namespace XCEngine {
+namespace Platform {
+
+class IDynamicLibrary {
+public:
+    virtual ~IDynamicLibrary() = default;
+
+    virtual bool Load(const char* path) = 0;
+    virtual void Unload() = 0;
+    virtual bool IsLoaded() const = 0;
+
+    virtual void* GetSymbol(const char* symbolName) = 0;
+    template<typename T>
+    T GetSymbol(const char* symbolName) {
+        return reinterpret_cast<T>(GetSymbol(symbolName));
+    }
+
+    virtual const char* GetPath() const = 0;
+};
+
+} // namespace Platform
+} // namespace XCEngine