Remove auto mask loading docs and clean up code comments

Deleted documentation files related to automatic mask loading. Cleaned up and streamlined comments across Canvas.js, CanvasInteractions.js, CanvasLayers.js, CanvasView.js, MaskTool.js, mask_utils.js, and example scripts for improved clarity and maintainability. No functional changes to core logic.

js/CanvasInteractions.js

@@ -194,8 +194,7 @@ export class CanvasInteractions {
             this.resetInteractionState();
             this.canvas.render();
         }
-        
-        // Clear internal clipboard when mouse leaves canvas
+
         if (this.canvas.canvasLayers.internalClipboard.length > 0) {
             this.canvas.canvasLayers.internalClipboard = [];
             log.info("Internal clipboard cleared - mouse left canvas");