Rivet theme settings are missing configuration schema

Problem/Motivation

Rivet ships config/install/rivet.settings.yml and adds several custom values through its theme settings form, but it does not provide a corresponding config/schema/rivet.schema.yml file.

Consequently, Drupal's typed configuration manager does not recognize rivet.settings as having configuration schema. Configuration inspection and schema-validation workflows report the object as having no schema.

Rivet currently stores the following custom settings:

• site_name
• subtitle
• hide_home_breadcrumb
• footer_variant
• privacy_url
• sidebar_border_right
• page_width
• content_width

Core's standard theme_settings schema type covers common settings such as the logo, favicon, and optional features, but it does not describe these Rivet-specific keys.

Inherited Rivet subthemes have separately named configuration objects such as my_subtheme.settings. Those subthemes also need a schema declaration that extends Rivet's settings schema. Generated Rivet starterkit themes should receive an appropriately renamed schema file.

Steps to reproduce

1. Install Rivet on a supported Drupal version.
2. Run: drush php:eval '$typed = \Drupal::service("config.typed"); var_export($typed->hasConfigSchema("rivet.settings"));'
3. Observe that the command returns false.
4. Alternatively, with Config Inspector enabled, run:
   

   drush config:inspect --only-error --filter-keys='rivet.settings'

5. Observe that rivet.settings is reported as having no schema.

This was reproduced with Rivet 1.2.x development code on Drupal 11.4.12.

Proposed resolution

• Add config/schema/rivet.schema.yml.
• Define rivet.settings as extending core's theme_settings type.
• Provide mappings for every Rivet-specific setting, using appropriate string and boolean types.
• Add choice constraints for settings with fixed options where practical.
• Ensure Rivet starterkit generation copies and renames the schema for the generated theme.
• Document that an inherited subtheme should declare its settings schema using Rivet's definition, for example:
  

  my_subtheme.settings:
    type: rivet.settings
    label: 'My subtheme settings'

• Add automated coverage confirming that Rivet's default and form-submitted settings comply with the schema on supported Drupal versions.

Remaining tasks

• [ ] Add the Rivet configuration schema.
• [ ] Add schema-validation test coverage.
• [ ] Verify the generated starterkit theme has correctly renamed schema.
• [ ] Verify and document schema inheritance for Rivet subthemes.
• [ ] Review and merge.

User interface changes

None.

API changes

Adds typed configuration metadata for Rivet theme settings. No PHP API changes.

Data model changes

None. Existing configuration values are unchanged; this adds schema metadata describing them.