How can authentication details be stored json-ld compliant way? - json

Question

This may be a dumb question, but I am architecting a web app from scratch and looking for content to be stored in MongoDB in a JSON-LD compliant way.
My user Schema looks something like this:
{"auth": {
"local": {
"email": String,
"password": String,
},
"firebase" : {
"uid" : String
},
"facebook": {
"id" : String,
"token" : String,
"email" : String,
"name" : String
}
},
"profile_contents" : {
"id" : {
"firstname" : {"value": String},
"lastname" : {"value": String},
"email" : [String],
"dob": Date,
"gender": {type: String, enum: genderTypes}
},
"profile" : {
"displayName": String,
"img": String,
"website" : String,
"organisation": String
}
}}
Questions:
Most of the content in the id and profile objects will make its way to a restful endpoint. It makes sense for these to be mapped to schemas. But the Auth object will rarely (never?) be exposed to the API and will be used for backend operations.. should these still be mapped to a schema, if so, how?
Regardless of the answer to (1) are there scehmas suited to mapping credentials like those listed? (e.g. suppose we want to expose auth.firebase.uid at one point.. should this be part of a custom vocab or mapped to an already existing one? Schema.org didn't have anything (other than accountId - which seems to be aimed at eCommerce payment use cases).
Thanks!