WA-VERIFY-112: verify Rails 7.1 ActiveRecord attribute API assumptions

[kitcommerce]

Summary

• audit Workarea for ActiveRecord attribute API touchpoints relevant to Rails 7.1 migration paths
• document the mixed-persistence boundaries reviewed and why they do not depend on ActiveRecord internals
• record the local verification blocker encountered while attempting to run focused tests in this checkout

Testing

• repo search for read_attribute, write_attribute, attribute_before_type_cast, attributes_before_type_cast, attribute_types, type_for_attribute, column_for_attribute, direct attributes[...] mutation, as_document, instantiate, and Mongoid::Factory.from_db
• reviewed focused code paths in Content, Release::Changeset, Pricing::Request, serializer, and view-model rehydration boundaries
• attempted to run:
  • bundle exec ruby -Itest core/test/models/workarea/content_test.rb
  • bundle exec ruby -Itest core/test/models/workarea/release/changeset_test.rb
  • bundle exec ruby -Itest core/test/elasticsearch/workarea/elasticsearch/serializer_test.rb
• local test execution is currently blocked before boot by Bundler failing to parse workarea.gemspec required_ruby_version in this checkout/toolchain

Findings

• no Rails 7.1 incompatibility was found in the reviewed attribute-access and mixed-persistence code paths
• reviewed usages rely on Mongoid document/hash APIs or ActiveModel-compatible dirty/attribute APIs rather than ActiveRecord internal attribute containers
• added docs/verification/wa-verify-112-active-record-attribute-api.md with the full audit summary

Client impact

• None expected. This is a verification/docs-only change; no application behavior changed.