refactor(editor): extract editor management responsibilities into dedicated classes

- Introduced EditorRegistry, ProjectManager, and RomFileManager to streamline editor operations and improve code organization.
- Refactored EditorManager to delegate responsibilities to the new classes, enhancing maintainability and clarity.
- Updated CMake configuration to include new source files for the extracted components.

Benefits:
- Improves separation of concerns within the editor, leading to a more modular and manageable codebase.
- Enhances the overall architecture by clearly defining roles for editor management, project handling, and ROM file operations.

src/app/editor/system/project_manager.h

@@ -0,0 +1,70 @@
+#ifndef YAZE_APP_EDITOR_SYSTEM_PROJECT_MANAGER_H_
+#define YAZE_APP_EDITOR_SYSTEM_PROJECT_MANAGER_H_
+
+#include <string>
+
+#include "absl/status/status.h"
+#include "app/core/project.h"
+
+namespace yaze {
+namespace editor {
+
+class ToastManager;
+
+/**
+ * @class ProjectManager
+ * @brief Handles all project file operations
+ * 
+ * Extracted from EditorManager to provide focused project management:
+ * - Project creation and templates
+ * - Project loading and saving
+ * - Project import/export
+ * - Project validation and repair
+ */
+class ProjectManager {
+ public:
+  explicit ProjectManager(ToastManager* toast_manager);
+  ~ProjectManager() = default;
+
+  // Project file operations
+  absl::Status CreateNewProject(const std::string& template_name = "");
+  absl::Status OpenProject(const std::string& filename = "");
+  absl::Status SaveProject();
+  absl::Status SaveProjectAs(const std::string& filename = "");
+  
+  // Project import/export
+  absl::Status ImportProject(const std::string& project_path);
+  absl::Status ExportProject(const std::string& export_path);
+  
+  // Project maintenance
+  absl::Status RepairCurrentProject();
+  absl::Status ValidateProject();
+  
+  // Project information
+  core::YazeProject& GetCurrentProject() { return current_project_; }
+  const core::YazeProject& GetCurrentProject() const { return current_project_; }
+  bool HasActiveProject() const { return !current_project_.filepath.empty(); }
+  std::string GetProjectName() const;
+  std::string GetProjectPath() const;
+  
+  // Project templates
+  std::vector<std::string> GetAvailableTemplates() const;
+  absl::Status CreateFromTemplate(const std::string& template_name, 
+                                 const std::string& project_name);
+
+ private:
+  core::YazeProject current_project_;
+  ToastManager* toast_manager_ = nullptr;
+  
+  // Helper methods
+  absl::Status LoadProjectFromFile(const std::string& filename);
+  absl::Status SaveProjectToFile(const std::string& filename);
+  std::string GenerateProjectFilename(const std::string& project_name) const;
+  bool IsValidProjectFile(const std::string& filename) const;
+  absl::Status InitializeProjectStructure(const std::string& project_path);
+};
+
+}  // namespace editor
+}  // namespace yaze
+
+#endif  // YAZE_APP_EDITOR_SYSTEM_PROJECT_MANAGER_H_