v0.3.0

Changed

• BREAKING: postal addresses in ContactData / ContactInput now spell the
  postal code postalCode (was postCode) and the post-office box poBox (was
  pobox).
• BREAKING: the administrative subdivision is carried as region only; the
  parallel state field is gone. Mapping a source that reports a state onto
  region is the importer's job, keeping exactly one spelling per field in
  ContactInput. Documents stored under the old shape upgrade via
  upgradeContactData (see below).
• phoneNumbers entries can now carry digits, countryCode, and an id;
  emailAddresses entries can carry an id. All are optional, so an importer
  that has none of them produces the same output as before. Note the caveat
  documented on the fields: like the contact-level nativeId, a sub-record id
  can churn when a platform re-aggregates raw contacts across accounts, so treat
  it as a diff hint rather than permanent identity.
• ContactInput phone / email entries now take an optional, nullable number /
  email, so an importer can pass a source's entries straight through without
  pre-filtering. normalizeContact trims them and DROPS entries that are empty
  afterwards -- and it now does so before deciding whether the contact has any
  contact method at all, so a placeholder entry can no longer keep a nameless
  contact that has nothing to reach it by. Callers that relied on empty entries
  surviving normalization will see shorter arrays.
• isContactData checks the new field spellings and the new optional sub-record
  fields. It ignores fields it does not know, so a document stored under the old
  spellings still validates: decrypt, validate, and upgrade in whichever order
  suits the consumer.
• Documented ContactInput.birthday.month as 1-indexed (1 = January) at the
  contract boundary. normalizeContact requires month > 0, so an importer
  whose source uses the 0-indexed JS Date convention must add 1 before
  calling; passing a raw 0-indexed month silently drops every January birthday
  and shifts the rest back by one.

Added

• upgradeContactData, plus the upgradeContactHeadPayload /
  upgradeContactRevisionPayload conveniences, for the read path: renames
  postCode / pobox and folds state into region when region is absent.
  Apply it when loading stored head / revision documents so pre-change documents
  compare cleanly against a fresh import and last-write-wins sees no spurious
  edit. Input already in the current shape is returned unchanged, so it is
  idempotent and safe to apply on every load.