feat : composant MalioDate (datepicker) avec calendrier, vue mois, bornes et effacement (#MUI-33)

Sous-composants internes (CalendarHeader, MonthGrid, MonthPicker), composant
public Date.vue, tests d'intégration, story Histoire et page playground.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/story/date/datePicker.story.vue

@@ -0,0 +1,94 @@
+<template>
+  <Story title="Date/Date">
+    <div class="grid grid-cols-1 items-start gap-6 md:grid-cols-2">
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Simple</h2>
+        <MalioDate
+          v-model="simpleValue"
+          label="Date de naissance"
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Valeur initiale</h2>
+        <MalioDate
+          v-model="initialValue"
+          label="Date du jour"
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Avec min/max</h2>
+        <MalioDate
+          v-model="boundedValue"
+          label="Date du rendez-vous"
+          :min="todayIso"
+          :max="maxIso"
+          hint="Entre aujourd'hui et +30 jours"
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Non effaçable</h2>
+        <MalioDate
+          v-model="initialValue"
+          label="Date verrouillée"
+          :clearable="false"
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Désactivé</h2>
+        <MalioDate
+          v-model="initialValue"
+          label="Désactivé"
+          disabled
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Lecture seule</h2>
+        <MalioDate
+          v-model="initialValue"
+          label="Lecture seule"
+          readonly
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Erreur</h2>
+        <MalioDate
+          v-model="errorValue"
+          label="Date limite"
+          error="Date invalide"
+        />
+      </div>
+
+      <div class="rounded-lg border p-4">
+        <h2 class="mb-4 text-xl font-bold">Succès</h2>
+        <MalioDate
+          v-model="initialValue"
+          label="Date confirmée"
+          success="Enregistrée"
+        />
+      </div>
+    </div>
+  </Story>
+</template>
+
+<script setup lang="ts">
+import {ref} from 'vue'
+import MalioDate from '../../components/malio/date/Date.vue'
+
+const pad = (n: number) => String(n).padStart(2, '0')
+const toIso = (d: Date) => `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}`
+
+const now = new Date()
+const todayIso = toIso(now)
+const maxIso = toIso(new Date(now.getTime() + 30 * 86400000))
+
+const simpleValue = ref<string | null>(null)
+const initialValue = ref<string | null>(todayIso)
+const boundedValue = ref<string | null>(null)
+const errorValue = ref<string | null>(null)
+</script>