✨ feat(mobile): add BottomBar navigation and CheminLibre drawer (Story 3.7)

- Add ZoneCard component for zone display with status indicators
- Add CheminLibre drawer with vertical zone cards and path decoration
- Add BottomBar with Map, Progress, and Settings buttons
- Add ProgressDetail modal showing visited sections
- Add SettingsDrawer with language, consent, and reset options
- Add i18n translations for zone, cheminLibre, bottomBar, settings
- Add --bottom-bar-height CSS variable for spacing
- Modify layouts to include BottomBar on mobile (< 768px)
- Support safe-area-inset for iOS devices
- Touch targets minimum 48x48px for WCAG compliance

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

frontend/app/layouts/adventure.vue

@@ -19,11 +19,11 @@ onMounted(() => {
   <div class="min-h-screen bg-sky-dark text-sky-text flex flex-col">
     <LayoutAppHeader />
 
-    <main class="flex-1">
+    <main class="flex-1 pb-mobile-nav md:pb-0">
       <slot />
     </main>
 
-    <LayoutAppFooter />
+    <LayoutAppFooter class="hidden md:block" />
 
     <ClientOnly>
       <LayoutConsentBanner />
@@ -36,5 +36,21 @@ onMounted(() => {
         @close="narrator.hide()"
       />
     </ClientOnly>
+
+    <ClientOnly>
+      <LayoutBottomBar />
+    </ClientOnly>
   </div>
 </template>
+
+<style scoped>
+.pb-mobile-nav {
+  padding-bottom: calc(var(--bottom-bar-height, 64px) + 1rem);
+}
+
+@media (min-width: 768px) {
+  .pb-mobile-nav {
+    padding-bottom: 0;
+  }
+}
+</style>