fix(errors) : humanize backend error messages for end users

Add centralized error translation layer (humanizeError) that converts
raw Symfony/Doctrine/API Platform messages into user-friendly French.
Fix useApi to extract errors from all backend response formats
(violations, error, message, hydra:description, detail).
Add toast deduplication to prevent double display. Replace error toast
icon (X → CircleX) to distinguish from the dismiss button.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/components/ToastContainer.vue

@@ -24,7 +24,7 @@
                 class="w-4 h-4"
                 aria-hidden="true"
               />
-              <IconLucideX
+              <IconLucideCircleX
                 v-else-if="toast.type === 'error'"
                 class="w-4 h-4"
                 aria-hidden="true"
@@ -64,6 +64,7 @@
 import { useToast } from '~/composables/useToast'
 import IconLucideCheck from '~icons/lucide/check'
 import IconLucideX from '~icons/lucide/x'
+import IconLucideCircleX from '~icons/lucide/circle-x'
 import IconLucideAlertTriangle from '~icons/lucide/alert-triangle'
 import IconLucideInfo from '~icons/lucide/info'
 

app/components/model-types/ManagementView.vue

@@ -119,6 +119,7 @@ import {
   type ModelTypeListResponse,
 } from "~/services/modelTypes";
 import { useToast } from "~/composables/useToast";
+import { humanizeError } from "~/shared/utils/errorMessages";
 import { invalidateEntityTypeCache } from "~/composables/useEntityTypes";
 
 const DEFAULT_DESCRIPTION =
@@ -183,7 +184,8 @@ useHead(() => ({
   title: headingText.value,
 }));
 
-const extractErrorMessage = (error: unknown) => {
+const extractErrorMessage = (error: unknown): string => {
+  let raw: string | null = null;
   if (error && typeof error === "object") {
     const maybeFetchError = error as {
       data?: Record<string, unknown>;
@@ -192,21 +194,16 @@ const extractErrorMessage = (error: unknown) => {
     };
     if (maybeFetchError.data) {
       const data = maybeFetchError.data;
-      if (typeof data.message === "string") {
-        return data.message;
-      }
-      if (Array.isArray(data.message) && data.message.length > 0) {
-        return data.message[0];
-      }
-    }
-    if (typeof maybeFetchError.statusMessage === "string") {
-      return maybeFetchError.statusMessage;
-    }
-    if (typeof maybeFetchError.message === "string") {
-      return maybeFetchError.message;
+      if (typeof data['hydra:description'] === "string") raw = data['hydra:description'];
+      else if (typeof data.detail === "string") raw = data.detail;
+      else if (typeof data.message === "string") raw = data.message;
+      else if (Array.isArray(data.message) && data.message.length > 0) raw = data.message[0];
+      else if (typeof data.error === "string") raw = data.error;
     }
+    if (!raw && typeof maybeFetchError.statusMessage === "string") raw = maybeFetchError.statusMessage;
+    if (!raw && typeof maybeFetchError.message === "string") raw = maybeFetchError.message;
   }
-  return "Une erreur est survenue lors de la communication avec le serveur.";
+  return humanizeError(raw);
 };
 
 const refresh = async ({