Introduces a new MaskTool for interactive mask drawing with adjustable brush size, strength, and softness. Updates Canvas.js to integrate mask editing, rendering, and saving, including support for saving images with and without masks. Enhances the UI in Canvas_view.js with mask controls and a dialog for canvas resizing. Updates canvas_node.py to load images without masks for processing. These changes improve user control over mask creation and management in the canvas workflow.
