{#- chirp-ui: Shell frame primitives — persistent-region contract

    Maps to Chirp's PageComposition model. Use shell_region for OOB targets
    (shell_actions, badges, breadcrumbs).

    Usage:
        {% from "chirpui/shell_frame.html" import shell_region %}

        <div id="{{ shell_actions_target }}" class="chirpui-app-shell__shell-actions">
          {% call shell_region(shell_actions_target) %}
            {{ shell_actions_bar(shell_actions) }}
          {% end %}
        </div>
-#}

{% def shell_region(id, cls="") %}
<div id="{{ id }}" class="chirpui-shell-region{{ " " ~ cls if cls else "" }}">
    {% slot %}
</div>
{% end %}