Include ActiveModel::API in ActiveRecord::Base

`ActiveRecord::Base` does not (and has never) inherit from
`ActiveModel::Model`.

`ActiveModel::API` was introduced in as an extraction from
`ActiveModel::Model`. At that time (Sep 15, 2021), it was included back
into `ActiveModel::Model`, but was never included in `ActiveRecord` at
all.

The intent communicated around the introduction of `ActiveModel::API`
stated:

> By moving `ActiveModel::Model`'s implementation to a new
> `ActiveModel::API` we keep a definition of the minimum API to talk with
> Action Pack and Action View.

Active Record is also designed to integrate with Action Pack and Action
View. It already does (and its integration predates `ActiveModel::API`
by more than a decade). It's integration is powered by including and
extending the same set of foundational modules, with some
database-specific overrides.

This commit adds an `include ActiveModel::API` statement to
`ActiveRecord::Base`, then re-structures those overrides to comply with
the new module resolution order.

[c477d95]: c477d95604

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Include `ActiveModel::API` in `ActiveRecord::Base`
+
+    *Sean Doyle*
+
 *   Ensure `#signed_id` outputs `url_safe` strings.
 
     *Jason Meller*

activerecord/lib/active_record/attribute_assignment.rb

@@ -2,8 +2,6 @@
 
 module ActiveRecord
   module AttributeAssignment
-    include ActiveModel::AttributeAssignment
-
     private
       def _assign_attributes(attributes)
         multi_parameter_attributes = nested_parameter_attributes = nil

activerecord/lib/active_record/base.rb

@@ -280,7 +280,7 @@ module ActiveRecord # :nodoc:
   # So it's possible to assign a logger to the class through <tt>Base.logger=</tt> which will then be used by all
   # instances in the current object space.
   class Base
-    extend ActiveModel::Naming
+    include ActiveModel::API
 
     extend ActiveSupport::Benchmarkable
     extend ActiveSupport::DescendantsTracker
@@ -304,7 +304,6 @@ class Base
     include Scoping
     include Sanitization
     include AttributeAssignment
-    include ActiveModel::Conversion
     include Integration
     include Validations
     include CounterCache

activerecord/lib/active_record/core.rb

@@ -428,7 +428,7 @@ def initialize(attributes = nil)
       init_internals
       initialize_internals_callback
 
-      assign_attributes(attributes) if attributes
+      super
 
       yield self if block_given?
       _run_initialize_callbacks

activerecord/lib/active_record/translation.rb

@@ -2,8 +2,6 @@
 
 module ActiveRecord
   module Translation
-    include ActiveModel::Translation
-
     # Set the lookup ancestors for ActiveModel.
     def lookup_ancestors # :nodoc:
       klass = self

activerecord/lib/active_record/validations.rb

@@ -39,7 +39,6 @@ def initialize(record = nil)
   # {new_record?}[rdoc-ref:Persistence#new_record?].
   module Validations
     extend ActiveSupport::Concern
-    include ActiveModel::Validations
 
     # The validation process on save can be skipped by passing <tt>validate: false</tt>.
     # The validation context can be changed by passing <tt>context: context</tt>.