Set x-keep-typed-in-additional-properties on UsageSummary schemas (#3493)

* Support x-keep-typed-in-additional-properties in Ruby model generator

When a schema sets `x-keep-typed-in-additional-properties: true`, also add
typed property keys to `additional_properties` so all fields are accessible
from a single map regardless of when they were added to the spec.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: copy typed fields into additional_properties after coercion, not before

The previous approach stored the raw pre-coercion hash value. After setters run,
self.attr_name holds the coerced value. We now copy post-coercion so both access
paths return consistent types.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Regenerate client from commit 3677df7 of spec repo

---------

Co-authored-by: Charlie Zhang <charlie.zhang@datadoghq.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: 4 people

.generator/schemas/v1/openapi.yaml

@@ -24110,6 +24110,7 @@ components:
           format: int64
           type: integer
       type: object
+      x-keep-typed-in-additional-properties: true
     UsageSummaryDateOrg:
       description: |-
         Global hourly report of all data billed by Datadog for a given organization.
@@ -25429,6 +25430,7 @@ components:
           format: int64
           type: integer
       type: object
+      x-keep-typed-in-additional-properties: true
     UsageSummaryResponse:
       description: |-
         Response summarizing all usage aggregated across the months in the request for
@@ -26776,6 +26778,7 @@ components:
           format: int64
           type: integer
       type: object
+      x-keep-typed-in-additional-properties: true
     UsageSyntheticsAPIHour:
       description: Number of Synthetics API tests run for each hour for a given organization.
       properties:

.generator/src/generator/templates/model_generic.j2

@@ -101,6 +101,11 @@
         {%- endif %}
       end
 {%- endfor %}
+{%- if model.get("x-keep-typed-in-additional-properties") %}
+{%- for attr, definition in model.get("properties", {}).items() %}
+      self.additional_properties[:'{{ attr|attribute_name }}'] = self.{{ attr|attribute_name }} if attributes.key?(:'{{ attr|attribute_name }}')
+{%- endfor %}
+{%- endif %}
     end
 
 {%- set ns = namespace(hasValidation=False) %}