Sharing data (json) between Node-red Editor (Nodes) and custom editor theme comonents

You will probably need to create a node-red plug-in to capture the "deploy" event. From there, you could store this "data" (whatever that is) in memory or file, ready for the client side request for it.

To access this "data", you can request it (via http/AJAX) from client side to node-red. Here is an example: Async getting list for node config - #4 by Steve-Mcl
This endpoint would typically be created in your plug-in.