v8.0.0

Added

• user_communication_methods.qualifier — an optional, nullable free-text
  label on a contact method, for distinguishing two methods of the same channel
  (e.g. a "work" vs "home" phone). The value is consumer-defined; the library
  never interprets, requires, or populates it. Consumers that carried a ucm
  extend solely for this column can drop it.
• auth_create_user accepts an optional qualifier on each
  communication_methods entry and stores it verbatim (absent → NULL), so a
  consumer that wants to set a label no longer needs a follow-up UPDATE.

Changed

• auth_create_user now raises a friendly, catchable duplicate-contact
  error. When a requested (channel, code) already belongs to a live
  communication method, the function raises SQLSTATE 23505
  (unique_violation) with a message naming the channel
  (a user with this email already exists) instead of letting a raw constraint
  violation escape. 23505 is raised only for this case — every other failure
  carries the default P0001 code — so a consumer can map a duplicate contact to
  a 4xx ("that email/phone is already in use") without parsing constraint
  names.

Security

• tenants.slug now carries a DNS-label format CHECK
  (tenants_slug_format_check). The slug is the tenant sub-domain
  (acme.app.com), so it must be a valid DNS label — lowercase alphanumerics
  with internal hyphens, no leading/trailing hyphen. An invalid slug (an
  unroutable host) is now rejected at the database instead of relying on every
  consumer to re-declare the check. The constraint is NULL-safe, since slug is
  optional. Existing rows with a non-conforming slug must be corrected before
  migrating.