Layout subtype ignored when shapes array reference is modified

[zstoyanova9]

Description

When the shapes array reference changes (whether by creating a new reference with spread operator, replacing the array entirely, etc.), the defined layout subtype property is ignored. For example, a layout configured as { type: 'tree', subtype: 'right' } renders with a "down" subtype instead.

Steps To Reproduce

1. Open the following example - https://stackblitz.com/edit/angular-chtgh6my
2. Click the "Add shape" button and see how the layout of the Diagram changes.

Actual Behavior

The subtype property is ignored and the layout defaults to "down".

Expected Behavior

The layout's subtype property should be preserved and applied correctly after adding a new shape.

[mtlljm]

I experienced a similar issue, when the shapes input changes, the component triggers a re-layout, which automatically repositions shapes according to the default layout algorithm, overriding any programmatically set layout positions, or any manually positioned items.

I tracked it down to this code.

if (changes['shapes'] || changes['connections'] || changes['shapeModelFields'] || changes['connectionModelFields']) {
            this.convertUserData();
            this.options = {
                ...this.options,
                shapes: this.convertedShapes,
                connections: this.convertedConnections
            };
            this.loadOptions(this.options);

....
....
loadOptions(options) {
        this.diagramWidget?.load(options);
        this.diagramWidget?.layout(options);
}```