fix(sidebar) : le hamburger pilote le repli + suppression du code de tiroir mobile mort

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

frontend/shared/stores/ui.ts

@@ -1,6 +1,5 @@
 export const useUiStore = defineStore('ui', () => {
     const sidebarCollapsed = ref(false)
-    const sidebarOpen = ref(false)
     const darkMode = ref(false)
 
     if (import.meta.client) {
@@ -45,13 +44,5 @@ export const useUiStore = defineStore('ui', () => {
         sidebarCollapsed.value = !sidebarCollapsed.value
     }
 
-    function openMobileSidebar() {
-        sidebarOpen.value = true
-    }
-
-    function closeMobileSidebar() {
-        sidebarOpen.value = false
-    }
-
-    return { sidebarCollapsed, sidebarOpen, darkMode, toggleSidebar, openMobileSidebar, closeMobileSidebar, toggleDarkMode }
+    return { sidebarCollapsed, darkMode, toggleSidebar, toggleDarkMode }
 })