feat: add clear history button with confirmation on ArticleHistory page

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/articleHistory.ts

@@ -14,4 +14,7 @@ export const articleHistoryApi = {
 
   getProvenance: (synthesisId: string): Promise<ArticleHistoryEntry[]> =>
     api.get<ArticleHistoryEntry[]>(`/syntheses/${synthesisId}/provenance`),
+
+  clearAll: (): Promise<{ deleted: number }> =>
+    api.delete<{ deleted: number }>('/article-history'),
 };

frontend/src/i18n/fr.ts

@@ -348,6 +348,9 @@ const fr = {
   'articleHistory.provenance': 'Provenance',
   'articleHistory.provenanceEmpty': 'Aucune donnee de provenance disponible pour cette synthese.',
   'articleHistory.provenanceDescription': 'Articles candidats traites lors de la generation de cette synthese.',
+  'articleHistory.clearAll': 'Effacer l\'historique',
+  'articleHistory.clearConfirm': 'Etes-vous sur de vouloir effacer tout l\'historique des articles ? Cette action est irreversible.',
+  'articleHistory.cleared': 'Historique efface',
 
   // LLM Logs
   'llmLogs.title': 'Logs des appels IA',

frontend/src/pages/ArticleHistory.tsx

@@ -55,6 +55,7 @@ const ArticleHistory: Component = () => {
   const [filterStatus, setFilterStatus] = createSignal('');
   const [filterSourceType, setFilterSourceType] = createSignal('');
   const [page, setPage] = createSignal(0);
+  const [confirming, setConfirming] = createSignal(false);
 
   const totalPages = () => Math.max(1, Math.ceil(total() / PAGE_SIZE));
 
@@ -88,6 +89,22 @@ const ArticleHistory: Component = () => {
     // Skip the initial run which is handled by onMount
   });
 
+  const handleClear = async () => {
+    if (!confirming()) {
+      setConfirming(true);
+      setTimeout(() => setConfirming(false), 3000);
+      return;
+    }
+    try {
+      await articleHistoryApi.clearAll();
+      setConfirming(false);
+      setPage(0);
+      fetchHistory();
+    } catch (err) {
+      console.error('Failed to clear history', err);
+    }
+  };
+
   const handleFilterChange = () => {
     setPage(0);
     fetchHistory();
@@ -101,10 +118,20 @@ const ArticleHistory: Component = () => {
   return (
     <div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
       {/* Page header */}
-      <div class="mb-6">
+      <div class="mb-6 flex items-center justify-between">
         <h1 class="text-3xl font-bold text-gray-900">
           {t('articleHistory.title')}
         </h1>
+        <button
+          onClick={handleClear}
+          class={`px-3 py-1.5 text-sm rounded-md border ${
+            confirming()
+              ? 'bg-red-600 text-white border-red-600'
+              : 'bg-white text-red-600 border-red-300 hover:bg-red-50'
+          }`}
+        >
+          {confirming() ? 'Confirmer' : t('articleHistory.clearAll')}
+        </button>
       </div>
 
       {/* Filters */}