feat(Resources): Add ResourceDependencyGraph for resource dependency tracking

- Implement dependency graph for resource management
- Add/remove nodes and dependencies
- Reference counting support
- Circular dependency detection
- Add unit tests

engine/include/XCEngine/Resources/ResourceDependencyGraph.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#include "ResourceTypes.h"
+#include "../Containers/HashMap.h"
+#include "../Containers/Array.h"
+#include "../Core/Types.h"
+
+namespace XCEngine {
+namespace Resources {
+
+struct DependencyNode {
+    ResourceGUID guid;
+    ResourceType type;
+    Containers::Array<ResourceGUID> dependencies;
+    Containers::Array<ResourceGUID> dependents;
+    Core::uint32 refCount = 0;
+};
+
+class ResourceDependencyGraph {
+public:
+    ResourceDependencyGraph();
+    ~ResourceDependencyGraph();
+
+    void AddNode(ResourceGUID guid, ResourceType type);
+    void RemoveNode(ResourceGUID guid);
+
+    void AddDependency(ResourceGUID owner, ResourceGUID dependency);
+    void RemoveDependency(ResourceGUID owner, ResourceGUID dependency);
+
+    Containers::Array<ResourceGUID> GetDependencies(ResourceGUID guid) const;
+    Containers::Array<ResourceGUID> GetDependents(ResourceGUID guid) const;
+    Containers::Array<ResourceGUID> GetAllDependencies(ResourceGUID guid) const;
+
+    void IncrementRefCount(ResourceGUID guid);
+    void DecrementRefCount(ResourceGUID guid);
+    Core::uint32 GetRefCount(ResourceGUID guid) const;
+
+    bool HasCircularDependency(ResourceGUID guid, Containers::Array<ResourceGUID>& outCycle) const;
+
+    Containers::Array<ResourceGUID> TopologicalSort() const;
+
+    bool Unload(ResourceGUID guid);
+
+    void Clear();
+
+    bool HasNode(ResourceGUID guid) const;
+
+private:
+    bool HasCircularDependencyInternal(ResourceGUID guid, Containers::HashMap<ResourceGUID, bool>& visited, 
+                                       Containers::Array<ResourceGUID>& path, Containers::Array<ResourceGUID>& outCycle) const;
+
+    Containers::HashMap<ResourceGUID, DependencyNode> m_nodes;
+};
+
+} // namespace Resources
+} // namespace XCEngine