BPMN-/DMN-/CMMN-viewer/editor

I need an experienced Nextcloud developer for an open source Nextcloud app (initial setup) to integrate BPMN-/DMN-/CMMN-viewing and -editing into Nextcloud e.g. for collaboration in dispersed project teams. The BPMN 2.0 viewer/editor of course should be based on https://bpmn.io/. Knowledge of bpmn-js, dmn-js etc ist not needed.

BPMN/DMN/CMMN files of type *.bpmn / *.dmn / *.cmmn stored in Nextcloud can be opened by a click for a viewing / annotation / editing mode - depending on the users permissions.
The functionality should be similar to Nextcloud-draw.io-App or OnlyOffice.

I haven’t found this kind of app yet. There are some similar application/platforms out there, but none are based on Nextcloud.