Migrate product data from Kirby to Shopify Storefront API

- Add product loaders (product-loader.js, products-list-loader.js) to fetch data from Shopify
- Extend Shopify API client with getProductByHandle() and getAllProducts() methods
- Integrate Shopify metafields for multilingual support (custom.title_en, custom.description_en)
- Refactor product.php and home.php templates to load content dynamically
- Simplify product blueprint to minimal routing configuration
- Create generic buy-button.php snippet with variant selection
- Update footer.php with conditional script loading
- Refactor _section--product.scss for better Sass structure
- Add translations for loading states and product errors
- Clean up old Kirby product content files

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

site/templates/home.php

@@ -1,35 +1,24 @@
 <?php snippet('header', ['title' => $site->title(), 'template' => 'store']) ?>
 
-    <main>
-        <p class="p__baseline-big">
-            <?= $page->baseline()->or('Bienvenue sur la boutique de soutien à Index') ?>
-        </p>
+<main>
+    <p class="p__baseline-big">
+        <?= $page->baseline()->or('Bienvenue sur la boutique de soutien à Index') ?>
+    </p>
 
-        <section id="store__container">
-            <?php foreach($site->children()->listed() as $product): ?>
-            <article class="store__product">
-                <figure>
-                    <?php if($cover = $product->files()->sortBy('sort', 'asc')->first()): ?>
-                        <?php snippet('picture', [
-                            'file' => $cover,
-                            'alt' => $product->title()->html(),
-                            'preset' => 'product-card',
-                            'size' => 25,
-                            'lazy' => true
-                        ]) ?>
-                    <?php endif ?>
-                </figure>
-                <p class="line-1"><a href="<?= $product->url() ?>"><?= $product->title()->html() ?></a></p>
-                <p class="price"><?= $product->price() ?>€</p>
-                <a href="<?= $product->url() ?>" class="link-block" aria-hidden="true"></a>
-            </article>
-            <?php endforeach ?>
-        </section>
+    <section id="store__container"
+             data-products-loader
+             data-language="<?= strtoupper($kirby->language()->code()) ?>">
 
-        <p class="p__baseline-big">
-            <?= t('supportText', 'Pour nous soutenir, vous&nbsp;pouvez&nbsp;aussi') ?>
-            <a href="https://soutenir.index.ngo" class="link-don"><?= t('makeDonation', 'faire un don') ?></a>
-        </p>
-    </main>
+        <div class="products-loading">
+            <p><?= t('loading') ?></p>
+        </div>
+
+    </section>
+
+    <p class="p__baseline-big">
+        <?= t('supportText') ?>
+        <a href="https://soutenir.index.ngo" class="link-don"><?= t('makeDonation') ?></a>
+    </p>
+</main>
 
 <?php snippet('footer') ?>