Added draggable functionality to the batch preview menu, allowing users to reposition it within the canvas using world coordinates. The menu's position now updates with viewport changes, and its initial placement is centered below the output area. Also refactored logic to show the menu with new layers instead of adding to an existing batch.
Introduces an addLayers method to BatchPreviewManager for adding new layers to an active batch preview or showing the UI if inactive. Updates Canvas to use addLayers instead of show, and fixes a bug where new layers were only added if more than one was present.
BatchPreviewManager now automatically hides the mask overlay when batch preview starts and restores its previous state when preview ends. The mask toggle button's state and label are updated accordingly. Also, mask toggle button IDs are now unique per canvas node.
Introduces BatchPreviewManager for reviewing and confirming multiple imported layers after auto-refresh. Adds a toggle button for mask overlay visibility in the UI and updates mask rendering logic to respect overlay visibility. Also refactors image import to return new layers and adds a utility for removing layers by ID.
