Extending NC core mimetypes and icons (by NC app) while keeping NC integrity check passing

Gist

Asking for a feature (canonical way), for apps to be able to specify new mime types to NC core and upload icons for those mime(file) types.

Use case

There is an app that deals with viewing 3D files.

Upon install it injects mimetypes and uploads SVG icons (\OC::$SERVERROOT . '/core/img/filetypes/'). Upon uninstall it cleans itself up.

This results in integrity checks for core such as these

https://github.com/WARP-LAB/files_3dmodelviewer/issues/33#issuecomment-2766027024

INVALID_HASH
core/js/mimetypelist.js
EXTRA_FILE
core/img/filetypes/ply.svg
core/img/filetypes/stl.svg
core/img/filetypes/fcstd.svg
core/img/filetypes/off.svg
core/img/filetypes/step.svg
core/img/filetypes/3ds.svg
core/img/filetypes/glb.svg
core/img/filetypes/iges.svg
core/img/filetypes/bim.svg
core/img/filetypes/3dm.svg
core/img/filetypes/3mf.svg
core/img/filetypes/brep.svg
core/img/filetypes/mtl.svg
core/img/filetypes/gltf.svg
core/img/filetypes/obj.svg
core/img/filetypes/fbx.svg
core/img/filetypes/wrl.svg
core/img/filetypes/ifc.svg
core/img/filetypes/dae.svg

Start by examining core/js/mimetypelist.js, core/img/filetypes/, and the integrity-check results shown in the issue. Determine how an app could add MIME types and icons without modifying core files or triggering INVALID_HASH and EXTRA_FILE errors; done should include install and uninstall behavior that keeps the core integrity check passing.