[Initiative] Headless User Management Module

[juliuskrah]

Summary

Integrate headless user-management services as optional components shared by GitStore and OIDC flows.

Scope

In scope:

• Contract for profile/identity synchronization boundaries
• Support for external user-management systems (Kratos, ZITADEL, SuperTokens)
• No credentials stored in GitStore domain services

Out of scope:

• Building an in-house credential lifecycle platform

Acceptance Criteria

• User-management integration is optional and pluggable
• GitStore stores only commerce-domain user data
• Identity lifecycle events can sync to GitStore profile projection
• Docs define ownership boundaries between GitStore, OIDC, and user management

Tracking

• Milestone: TBD