user_mapping_provider support in jwt_config

[col-panic]

Description:

oidc_providers do support the inital mapping of values on user creation via

    user_mapping_provider:
      config:
        localpart_template: "{{ user.preferred_username }}"
        display_name_template: "{{ user.name }}"
        email_template: "{{ user.email }}"

Could this be equally provided for jwt_config? Here the only value
available seems to be subject_claim.

I'm currently working on updating the Java Client to Server library and I found this when working on https://github.com/col-panic/Matrix-ClientServer-API-java/blob/98ef8dc6392306f41757ac14600606fef4160ac8/src/main/java/de/jojii/matrixclientserver/Bot/Client.java#L104

Current config is

jwt_config:
    enabled: true
    issuer: "https://${EE_HOSTNAME}/keycloak/auth/realms/ElexisEnvironment"
    algorithm: RS256
    secret: |
      -----BEGIN PUBLIC KEY-----
      ${REALM_PUBLIC_KEY}
      -----END PUBLIC KEY-----
    subject_claim: "preferred_username"
    audiences:
        - "synapse"

[col-panic]

The jwt handler https://github.com/element-hq/synapse/blob/05576f0b4b4a1ba5e756cbd1f0a064751f233d83/synapse/handlers/jwt.py#L39C53-L39C68 seems to support a display name and config also seems to include it - https://github.com/element-hq/synapse/blob/05576f0b4b4a1ba5e756cbd1f0a064751f233d83/synapse/config/jwt.py#L41C59-L41C77

I have to test whether it is just missing from the documentation in https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#jwt_config

[col-panic]

#17708 whow - :) same thoughts!

[col-panic]

Thanks @EnneS