refactor : migrate UI to Malio layer-ui components (MalioButton, MalioDrawer, MalioSelectCheckbox)

- Replace all AppDrawer with MalioDrawer across 10 drawer components
- Replace native <button> with MalioButton/MalioButtonIcon in all pages and components
- Fix TimeTrackingExportDrawer: use MalioSelectCheckbox for multi-select filters
- Add Malio design system colors (m-btn-*, m-disabled, m-surface) to tailwind.config.ts
- Align toggle button heights with MalioButton (h-[40px])

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/components/ui/ConfirmDeleteTaskModal.vue

@@ -9,20 +9,18 @@
                         {{ $t('tasks.deleteConfirmMessage') }}
                     </p>
                     <div class="mt-6 flex justify-end gap-3">
-                        <button
-                            type="button"
-                            class="rounded-md border border-neutral-300 px-4 py-2 text-sm font-semibold text-neutral-700 hover:bg-neutral-50"
+                        <MalioButton
+                            variant="tertiary"
+                            label="Annuler"
+                            button-class="w-auto px-4"
                             @click="cancel"
-                        >
-                            Annuler
-                        </button>
-                        <button
-                            type="button"
-                            class="rounded-md bg-red-600 px-4 py-2 text-sm font-semibold text-white hover:bg-red-700"
+                        />
+                        <MalioButton
+                            variant="danger"
+                            label="Supprimer"
+                            button-class="w-auto px-4"
                             @click="$emit('confirm')"
-                        >
-                            Supprimer
-                        </button>
+                        />
                     </div>
                 </div>
             </div>