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/client/ClientDrawer.vue

@@ -1,5 +1,5 @@
 <template>
-    <AppDrawer v-model="isOpen" :title="isEditing ? $t('clients.editClient') : $t('clients.addClient')">
+    <MalioDrawer v-model="isOpen" :title="isEditing ? $t('clients.editClient') : $t('clients.addClient')">
         <form @submit.prevent="handleSubmit" class="flex flex-col gap-2">
             <MalioInputText
                 v-model="form.name"
@@ -35,16 +35,15 @@
             />
 
             <div class="mt-6 flex justify-end">
-                <button
-                    type="submit"
-                    class="rounded-md bg-primary-500 px-6 py-2 text-sm font-semibold text-white hover:bg-secondary-500 disabled:cursor-not-allowed disabled:opacity-50"
+                <MalioButton
+                    label="Enregistrer"
+                    button-class="w-auto px-6"
                     :disabled="isSubmitting"
-                >
-                    Enregistrer
-                </button>
+                    @click="handleSubmit"
+                />
             </div>
         </form>
-    </AppDrawer>
+    </MalioDrawer>
 </template>
 
 <script setup lang="ts">