[Matrixreq] Defining and describing the components of BundID authentication

Description

Once we clarified ticket #195 we need documentation to describe the BundID authentication components aiming to integrate MAS. This task is part of the BundID Authentication with MAS (MXID) work package.

Background information

See ConceptBoard for reference.

• Reference issue: https://gitlab.opencode.de/fitko/matrix-g2x/planning/-/work_items/60
• The following people may help during the clarification: Marco, Bernhard

Priority

• low (sometime in the future...)
• medium (important for the current project phase, no project delay yet according to sprint planning)
• high (important for the next sprint)
• utmost urgent (needs to be resolved during the current sprint)

History (documented by team::requirements)

• 21.08.25 : Waiting for clarification from BMDS on how to include AKDB in the project.

Next steps (defined by team::requirements)

• Bernhard from AKDB can provide the right documentation and flows describing how ZPB interact with the identity provider as part of the BE.