Migrate ProjectManager to dependency injection

- Created IProjectManager interface
- ProjectManager now implements IProjectManager
- Removed ProjectManager::Get() singleton
- Added IEditorContext::GetProjectManager()
- ProjectPanel now uses m_context->GetProjectManager() instead of singleton
- EditorContext owns ProjectManager instance

editor/src/Managers/ProjectManager.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "Core/AssetItem.h"
+#include "Core/IProjectManager.h"
 #include <vector>
 #include <string>
 #include <memory>
@@ -8,35 +9,31 @@
 namespace XCEngine {
 namespace Editor {
 
-class ProjectManager {
+class ProjectManager : public IProjectManager {
 public:
-    static ProjectManager& Get();
+    std::vector<AssetItemPtr>& GetCurrentItems() override;
+    int GetSelectedIndex() const override { return m_selectedIndex; }
+    void SetSelectedIndex(int index) override { m_selectedIndex = index; }
     
-    std::vector<AssetItemPtr>& GetCurrentItems();
-    int GetSelectedIndex() const { return m_selectedIndex; }
-    void SetSelectedIndex(int index) { m_selectedIndex = index; }
+    void NavigateToFolder(const AssetItemPtr& folder) override;
+    void NavigateBack() override;
+    void NavigateToIndex(size_t index) override;
+    bool CanNavigateBack() const override { return m_path.size() > 1; }
     
-    void NavigateToFolder(const AssetItemPtr& folder);
-    void NavigateBack();
-    void NavigateToIndex(size_t index);
-    bool CanNavigateBack() const { return m_path.size() > 1; }
+    std::string GetCurrentPath() const override;
+    size_t GetPathDepth() const override { return m_path.size(); }
+    std::string GetPathName(size_t index) const override;
     
-    std::string GetCurrentPath() const;
-    size_t GetPathDepth() const { return m_path.size(); }
-    std::string GetPathName(size_t index) const;
+    void Initialize(const std::string& projectPath) override;
+    void RefreshCurrentFolder() override;
     
-    void Initialize(const std::string& projectPath);
-    void RefreshCurrentFolder();
+    void CreateFolder(const std::string& name) override;
+    void DeleteItem(int index) override;
+    bool MoveItem(const std::string& sourceFullPath, const std::string& destFolderFullPath) override;
     
-    void CreateFolder(const std::string& name);
-    void DeleteItem(int index);
-    bool MoveItem(const std::string& sourceFullPath, const std::string& destFolderFullPath);
-    
-    const std::string& GetProjectPath() const { return m_projectPath; }
+    const std::string& GetProjectPath() const override { return m_projectPath; }
 
 private:
-    ProjectManager() = default;
-    
     AssetItemPtr ScanDirectory(const std::wstring& path);
     AssetItemPtr CreateAssetItem(const std::wstring& path, const std::wstring& nameW, bool isFolder);
     std::wstring GetCurrentFullPathW() const;