feat(ui) : MalioDate/DateTime exposent update:valid + saisie clavier DateTime (#MUI-43)

- MalioDate : event update:valid (malforme/hors-plage => false), emis au montage
- MalioDateTime : prop editable (saisie JJ/MM/AAAA HH:MM) + meme update:valid
- CalendarField : masque maska configurable via prop mask
- datetimeFormat : nouveau parseur parseDisplayToIsoDateTime
- fix test Date « Entree » (key 'Enter' reel vs trigger keydown.enter)
- doc COMPONENTS.md + CHANGELOG.md + champ editable dans le playground

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/components/malio/date/internal/CalendarField.vue

@@ -137,6 +137,7 @@ const props = withDefaults(
     success?: string
     clearable?: boolean
     editable?: boolean
+    mask?: string
     inputClass?: string
     labelClass?: string
     groupClass?: string
@@ -155,6 +156,7 @@ const props = withDefaults(
     success: '',
     clearable: true,
     editable: false,
+    mask: '##/##/####',
     inputClass: '',
     labelClass: '',
     groupClass: '',
@@ -172,7 +174,7 @@ const generatedId = useId()
 const root = ref<HTMLElement | null>(null)
 
 const draft = ref(props.displayValue)
-const maskaOptions = computed<MaskInputOptions>(() => ({mask: props.editable ? '##/##/####' : undefined}))
+const maskaOptions = computed<MaskInputOptions>(() => ({mask: props.editable ? props.mask : undefined}))
 const inputReadonly = computed(() => !props.editable || props.readonly || props.disabled)
 
 watch(() => props.displayValue, (value) => {