feat(v11-dg): mobile header page active + hamburger top-right + poignee carte-o + polish css

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

src/components/astro/MobileTabBar.astro

@@ -0,0 +1,71 @@
+---
+// MobileTabBar - indicateur de colonne active sur mobile (V1.1-D.1)
+// Ecoute l'event "swipe-position-change" emis par SwipeContainer.vue
+// Affiche : Journal | Carte | Insta - colonne active surlignee
+---
+<nav
+  id="mobile-tab-bar"
+  aria-label="Navigation colonnes"
+  class="fixed top-0 left-0 right-0 z-30 h-11 bg-white border-b border-neutral-200 flex items-stretch justify-around md:hidden"
+>
+  <button
+    type="button"
+    data-tab-index="0"
+    class="mobile-tab flex-1 text-sm px-2 border-b-2 transition-colors"
+    aria-label="Aller au journal"
+  >
+    Journal
+  </button>
+  <button
+    type="button"
+    data-tab-index="1"
+    class="mobile-tab flex-1 text-sm px-2 border-b-2 transition-colors"
+    aria-label="Aller à la carte"
+  >
+    Carte
+  </button>
+  <button
+    type="button"
+    data-tab-index="2"
+    class="mobile-tab flex-1 text-sm px-2 border-b-2 transition-colors"
+    aria-label="Aller à Instagram"
+  >
+    Insta
+  </button>
+</nav>
+
+<script>
+  const tabs = document.querySelectorAll<HTMLButtonElement>('.mobile-tab');
+
+  function setActive(pos: number) {
+    tabs.forEach((tab, i) => {
+      const active = i === pos;
+      tab.classList.toggle('text-neutral-900', active);
+      tab.classList.toggle('font-medium', active);
+      tab.classList.toggle('border-neutral-900', active);
+      tab.classList.toggle('text-neutral-400', !active);
+      tab.classList.toggle('border-transparent', !active);
+    });
+  }
+
+  // Etat initial depuis sessionStorage (cle utilisee par SwipeContainer.vue)
+  const saved = sessionStorage.getItem('pc-position');
+  const initial = saved !== null && !Number.isNaN(Number(saved)) ? Number(saved) : 1;
+  setActive(initial);
+
+  // Ecoute les changements de position emis par SwipeContainer.vue
+  document.addEventListener('swipe-position-change', (e: Event) => {
+    const detail = (e as CustomEvent<{ pos: number }>).detail;
+    if (detail && typeof detail.pos === 'number') {
+      setActive(detail.pos);
+    }
+  });
+
+  // Les boutons de la tab bar declenchent un scroll via un event custom
+  tabs.forEach((tab) => {
+    tab.addEventListener('click', () => {
+      const idx = Number(tab.dataset.tabIndex);
+      document.dispatchEvent(new CustomEvent('mobile-tab-scroll', { detail: { pos: idx } }));
+    });
+  });
+</script>