feat: add B2B organization directory group synchronization through RabbitMQ.

[shepilov]

Summary

This introduces support for b2b.group.* lifecycle events on the b2b exchange and replicates managed contact groups, group memberships, and related external contacts across all instances of an organization.

What Changed

• Added a new stack.b2b.group.lifecycle queue bound to:

  • b2b.group.created
  • b2b.group.updated
  • b2b.group.deleted
  • b2b.group.member.added
  • b2b.group.member.removed

• Added organization directory group sync logic:

  • creates/updates/deletes managed io.cozy.contacts.groups documents
  • uses stable group IDs derived from organizationId + external group id
  • stores external metadata under twakeDirectory
  • refuses to overwrite/delete unmanaged groups

• Added membership sync:

  • creates or reuses managed external contacts by email / Cozy URL
  • attaches/removes group relationships on contacts
  • supports members that only have an email, with workplace FQDN as optional data

• Extended user.created organization contact sync:

  • supports organizationId or organization domain resolution
  • copies existing managed groups and contacts from the organization instance to newly created member instances

• Added managed directory protections in the data API:

  • managed contacts/groups cannot be created, updated, or deleted through regular data routes
  • only the organization directory sync path owns those documents

• Added organization instance lookup by org_id:

  • new global by-orgid index
  • org instance and managed directory queries now paginate with CouchDB bookmarks