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/rating.html.twig

@@ -0,0 +1,40 @@
+{#
+ # Loop Product Rating (Bootstrap 5 Override)
+ #
+ # Renders star ratings for products in the shop loop.
+ #
+ # Expected context:
+ #   product - WC_Product object with:
+ #     .get_average_rating() - Average rating (0-5)
+ #     .get_review_count()   - Number of reviews
+ #   reviews_enabled - Whether reviews/ratings are enabled (boolean)
+ #
+ # WooCommerce PHP equivalent: loop/rating.php
+ #
+ # @package WcBootstrap
+ # @since 0.1.0
+ #}
+
+{% if reviews_enabled is not defined or reviews_enabled %}
+    {% if product is defined and product.get_average_rating() > 0 %}
+        {% set rating = product.get_average_rating() %}
+        {% set count = product.get_review_count() %}
+
+        <div class="wc-star-rating d-flex align-items-center gap-1 mb-1"
+             role="img"
+             aria-label="{{ __('%s out of 5 stars')|format(rating) }}">
+            {% for i in 1..5 %}
+                {% if i <= rating|round(0, 'floor') %}
+                    <i class="bi bi-star-fill text-warning" aria-hidden="true"></i>
+                {% elseif i - rating < 1 %}
+                    <i class="bi bi-star-half text-warning" aria-hidden="true"></i>
+                {% else %}
+                    <i class="bi bi-star text-warning" aria-hidden="true"></i>
+                {% endif %}
+            {% endfor %}
+            {% if count > 0 %}
+                <small class="text-body-secondary">({{ count }})</small>
+            {% endif %}
+        </div>
+    {% endif %}
+{% endif %}