N°8641 - Dashboard editor front-end first commit for Form SDK integration.

* No dashlet edition
* Dashboard are not persisted
* Unable to load a dashboard from an endpoint (refresh)
* Grid library need proper npm integration

node_modules/gridstack/dist/dd-manager.d.ts

@@ -0,0 +1,43 @@
+/**
+ * dd-manager.ts 12.3.2
+ * Copyright (c) 2021-2025 Alain Dumesny - see GridStack root license
+ */
+import { DDDraggable } from './dd-draggable';
+import { DDDroppable } from './dd-droppable';
+import { DDResizable } from './dd-resizable';
+/**
+ * Global state manager for all Drag & Drop instances.
+ *
+ * This class maintains shared state across all drag & drop operations,
+ * ensuring proper coordination between multiple grids and drag/drop elements.
+ * All properties are static to provide global access throughout the DD system.
+ */
+export declare class DDManager {
+    /**
+     * Controls drag operation pausing behavior.
+     * If set to true or a number (milliseconds), dragging placement and collision
+     * detection will only happen after the user pauses movement.
+     * This improves performance during rapid mouse movements.
+     */
+    static pauseDrag: boolean | number;
+    /**
+     * Flag indicating if a mouse down event was already handled.
+     * Prevents multiple handlers from processing the same mouse event.
+     */
+    static mouseHandled: boolean;
+    /**
+     * Reference to the element currently being dragged.
+     * Used to track the active drag operation across the system.
+     */
+    static dragElement: DDDraggable;
+    /**
+     * Reference to the drop target element currently under the cursor.
+     * Used to handle drop operations and hover effects.
+     */
+    static dropElement: DDDroppable;
+    /**
+     * Reference to the element currently being resized.
+     * Helps ignore nested grid resize handles during resize operations.
+     */
+    static overResizeElement: DDResizable;
+}