优化: CR-08 i18n batch2全量(ProjectDetail5处+TaskDetail16key+AiChat3处+store error fallback 23处+useAiSend 3处)+@/i18n路径统一+vite别名

src/i18n/en/ideas.ts

@@ -76,5 +76,11 @@ export default {
     confirmDelete: 'Delete idea "{title}"? This cannot be undone.',
     promoteFailed: 'Promotion failed',
     evalFailed: 'Evaluation failed',
+    // Error fallbacks (user-visible via state.error)
+    err: {
+      loadFailed: 'Failed to load ideas',
+      createFailed: 'Failed to create idea',
+      deleteFailed: 'Failed to delete idea',
+    },
   },
 }