feat(validation): add arktype form schemas and i18n keys

Introduces field-specific validation messages so toasts name the
exact field and rule that failed instead of a catch-all "tous les
champs sont requis".

src/utils/validate.ts

@@ -0,0 +1,29 @@
+import { ArkErrors } from 'arktype'
+import type { Type } from 'arktype'
+import type { Composer } from 'vue-i18n'
+import queueNotifService from '@/services/QueueNotifService'
+
+type TranslateFn = Composer['t']
+type MessageParams = Record<string, unknown>
+export type ParamsByPath = Record<string, MessageParams>
+
+export function validateAndNotify(
+  schema: Type,
+  data: unknown,
+  t: TranslateFn,
+  paramsByPath: ParamsByPath = {}
+): boolean {
+  const result = schema(data)
+  if (!(result instanceof ArkErrors)) return true
+
+  const seen = new Set<string>()
+  for (const error of result) {
+    const pathKey = error.path.join('.')
+    // Skip duplicate field-level errors at the same path so the user gets one toast per field.
+    if (seen.has(pathKey)) continue
+    seen.add(pathKey)
+    const params = paramsByPath[pathKey] ?? {}
+    queueNotifService.error(t(error.message, params))
+  }
+  return false
+}