Implement Phase 2: product archive and shop loop templates (Bootstrap 5)

Add 15 Twig template overrides for the product archive and shop loop:
- archive-product: 3+9 grid layout with optional filter sidebar
- content-product: card component with hook-based content injection
- content-product-cat: category card with thumbnail
- product-searchform: input-group with search icon button
- loop/loop-start, loop-end: responsive row-cols grid
- loop/header: archive title with description hook
- loop/result-count: showing X-Y of Z with aria-relevant
- loop/orderby: form-select-sm sort dropdown
- loop/pagination: delegates to components/pagination.html.twig
- loop/no-products-found: alert-info empty state
- loop/add-to-cart: btn-primary-sm with AJAX data attributes
- loop/price: fw-semibold with sale/regular markup
- loop/rating: Bootstrap Icon stars (full, half, empty)
- loop/sale-flash: badge bg-danger positioned overlay

CSS additions: product card hover, sale badge z-index, star rating sizing,
price del/ins styling, WooCommerce grid reset.

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

templates/loop/orderby.html.twig

@@ -0,0 +1,40 @@
+{#
+ # Catalog Ordering / Sort Dropdown (Bootstrap 5 Override)
+ #
+ # Renders the product sort-by dropdown as a Bootstrap 5 form-select.
+ #
+ # Expected context:
+ #   catalog_orderby_options - Associative array of { value: label } sort options
+ #   orderby                - Currently selected orderby value
+ #   use_label              - Whether to display a label (boolean)
+ #
+ # WooCommerce PHP equivalent: loop/orderby.php
+ #
+ # @package WcBootstrap
+ # @since 0.1.0
+ #}
+
+<form class="woocommerce-ordering d-inline-block" method="get">
+    {% if use_label is defined and use_label %}
+        <label for="woocommerce-orderby" class="form-label visually-hidden">
+            {{ __('Sort by') }}
+        </label>
+    {% endif %}
+
+    <select name="orderby"
+            id="woocommerce-orderby"
+            class="form-select form-select-sm"
+            aria-label="{{ __('Shop order') }}"
+            onchange="this.form.submit()">
+        {% if catalog_orderby_options is defined %}
+            {% for value, label in catalog_orderby_options %}
+                <option value="{{ value|esc_attr }}"{% if value == orderby %} selected{% endif %}>
+                    {{ label|esc_html }}
+                </option>
+            {% endfor %}
+        {% endif %}
+    </select>
+
+    <input type="hidden" name="paged" value="1" />
+    {{ wc_query_string_form_fields() }}
+</form>