feature: integrate Donorbox API for donation management

- Add Donorbox configuration in site/config/config.php with API settings
- Create controller for support page to fetch campaign data from API
- Update support.php template with dynamic donation buttons and gauge
- Transform static buttons into dynamic links with proper URL parameters
- Add JavaScript for tab switching between one-time and monthly donations
- Calculate donation percentage and display real-time campaign stats

The donation buttons now link directly to Donorbox with pre-filled amounts
and intervals. API integration is ready but requires API key configuration.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

assets/js/donation-tabs.js

@@ -0,0 +1,59 @@
+/**
+ * Gestion des onglets de donation (ponctuel / mensuel)
+ */
+document.addEventListener('DOMContentLoaded', function() {
+    const tabButtons = document.querySelectorAll('.nav--tabs__btn');
+    const donationLinks = document.querySelectorAll('.btn--donation[data-amount]');
+
+    if (tabButtons.length === 0 || donationLinks.length === 0) return;
+
+    tabButtons.forEach(button => {
+        button.addEventListener('click', function() {
+            // Retirer la classe is-selected de tous les boutons
+            tabButtons.forEach(btn => btn.classList.remove('is-selected'));
+
+            // Ajouter la classe is-selected au bouton cliqué
+            this.classList.add('is-selected');
+
+            // Récupérer l'intervalle (o = ponctuel, m = mensuel)
+            const interval = this.getAttribute('data-interval');
+
+            // Mettre à jour les liens de donation
+            donationLinks.forEach(link => {
+                const amount = link.getAttribute('data-amount');
+                const currentHref = link.getAttribute('href');
+
+                // Remplacer l'intervalle dans l'URL
+                const newHref = currentHref.replace(
+                    /default_interval=[om]/,
+                    `default_interval=${interval}`
+                );
+
+                link.setAttribute('href', newHref);
+
+                // Mettre à jour le texte (ajouter /mois pour mensuel)
+                const amountSpan = link.querySelector('.amount-value');
+                const boldText = link.querySelector('.bold');
+
+                if (amountSpan && boldText) {
+                    if (interval === 'm') {
+                        boldText.innerHTML = `<span class="amount-value">${amount}</span>€/mois`;
+                    } else {
+                        boldText.innerHTML = `<span class="amount-value">${amount}</span>€`;
+                    }
+                }
+            });
+
+            // Mettre à jour aussi le lien "Montant libre"
+            const freeAmountLink = document.querySelector('.btn--donation:not([data-amount])');
+            if (freeAmountLink) {
+                const currentHref = freeAmountLink.getAttribute('href');
+                const newHref = currentHref.replace(
+                    /default_interval=[om]/,
+                    `default_interval=${interval}`
+                );
+                freeAmountLink.setAttribute('href', newHref);
+            }
+        });
+    });
+});