feat: add error handling with toast notifications across various tools and admin page

frontend/src/components/layout/SiteAssistant.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef, useState } from 'react';
 import { useLocation } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
 import { Bot, SendHorizontal, Sparkles, X } from 'lucide-react';
+import { toast } from 'sonner';
 import { getToolSEO } from '@/config/seoData';
 import { streamAssistantChat, type AssistantHistoryMessage } from '@/services/api';
 import { trackEvent } from '@/services/analytics';
@@ -181,6 +182,7 @@ export default function SiteAssistant() {
         ? requestError.message
         : t('assistant.unavailable');
       setError(message);
+      toast.error(message);
 
       setMessages((currentMessages) => currentMessages.map((currentMessage) => (
         currentMessage.id === assistantMessageId

frontend/src/components/tools/BarcodeGenerator.tsx

@@ -6,6 +6,7 @@ import ProgressBar from '@/components/shared/ProgressBar';
 import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 const BARCODE_TYPES = ['code128', 'code39', 'ean13', 'ean8', 'upca', 'isbn13', 'isbn10', 'issn', 'pzn'] as const;
@@ -32,7 +33,9 @@ export default function BarcodeGenerator() {
       });
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to generate barcode.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/CropPdf.tsx

@@ -9,6 +9,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 export default function CropPdf() {
@@ -40,7 +41,9 @@ export default function CropPdf() {
       const res = await api.post<TaskResponse>('/pdf-tools/crop', fd);
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to crop PDF.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/ImageCrop.tsx

@@ -9,6 +9,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 export default function ImageCrop() {
@@ -40,7 +41,9 @@ export default function ImageCrop() {
       const res = await api.post<TaskResponse>('/image/crop', fd);
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to crop image.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/ImageRotateFlip.tsx

@@ -9,6 +9,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 export default function ImageRotateFlip() {
@@ -41,7 +42,9 @@ export default function ImageRotateFlip() {
       const res = await api.post<TaskResponse>('/image/rotate-flip', fd);
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to transform image.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/ImagesToPdf.tsx

@@ -6,6 +6,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import ProgressBar from '@/components/shared/ProgressBar';
 import DownloadButton from '@/components/shared/DownloadButton';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
+import { toast } from 'sonner';
 import { uploadFiles } from '@/services/api';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
@@ -66,7 +67,9 @@ export default function ImagesToPdf() {
       setTaskId(data.task_id);
       setPhase('processing');
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Upload failed.');
+      const msg = err instanceof Error ? err.message : t('common.errors.uploadFailed');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setIsUploading(false);
     }

frontend/src/components/tools/MergePdf.tsx

@@ -7,6 +7,7 @@ import ProgressBar from '@/components/shared/ProgressBar';
 import DownloadButton from '@/components/shared/DownloadButton';
 import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
+import { toast } from 'sonner';
 import { uploadFiles } from '@/services/api';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
@@ -66,7 +67,9 @@ export default function MergePdf() {
       setTaskId(data.task_id);
       setPhase('processing');
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Upload failed.');
+      const msg = err instanceof Error ? err.message : t('common.errors.uploadFailed');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setIsUploading(false);
     }

frontend/src/components/tools/PdfFlowchart.tsx

@@ -4,6 +4,7 @@ import { Helmet } from 'react-helmet-async';
 import { GitBranch } from 'lucide-react';
 import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
+import { toast } from 'sonner';
 import { startTask, uploadFile } from '@/services/api';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
@@ -91,7 +92,9 @@ export default function PdfFlowchart() {
       const data = await uploadFile('/flowchart/extract', file);
       setTaskId(data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Upload failed.');
+      const msg = err instanceof Error ? err.message : t('common.errors.uploadFailed');
+      setError(msg);
+      toast.error(msg);
       setUploading(false);
     }
   };
@@ -104,7 +107,9 @@ export default function PdfFlowchart() {
       const data = await startTask('/flowchart/extract-sample');
       setTaskId(data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Sample failed.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setUploading(false);
     }
   };

frontend/src/components/tools/PdfMetadata.tsx

@@ -9,6 +9,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 export default function PdfMetadata() {
@@ -37,7 +38,9 @@ export default function PdfMetadata() {
       const res = await api.post<TaskResponse>('/pdf-tools/metadata', fd);
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to edit metadata.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/QrCodeGenerator.tsx

@@ -6,6 +6,7 @@ import ProgressBar from '@/components/shared/ProgressBar';
 import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
+import { toast } from 'sonner';
 import api, { type TaskResponse, type TaskResult } from '@/services/api';
 import { dispatchRatingPrompt } from '@/utils/ratingPrompt';
 
@@ -31,7 +32,9 @@ export default function QrCodeGenerator() {
       const res = await api.post<TaskResponse>('/qrcode/generate', { data: data.trim(), size });
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to generate QR code.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/components/tools/SignPdf.tsx

@@ -9,6 +9,7 @@ import AdSlot from '@/components/layout/AdSlot';
 import { useTaskPolling } from '@/hooks/useTaskPolling';
 import { generateToolSchema } from '@/utils/seo';
 import { useFileStore } from '@/stores/fileStore';
+import { toast } from 'sonner';
 import api, { type TaskResponse } from '@/services/api';
 
 export default function SignPdf() {
@@ -40,7 +41,9 @@ export default function SignPdf() {
       const res = await api.post<TaskResponse>('/pdf-tools/sign', fd);
       setTaskId(res.data.task_id);
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to sign PDF.');
+      const msg = err instanceof Error ? err.message : t('common.errors.processingFailed');
+      setError(msg);
+      toast.error(msg);
       setPhase('done');
     }
   };

frontend/src/pages/InternalAdminPage.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useMemo, useState, type FormEvent } from 'react';
+import { toast } from 'sonner';
 import { Helmet } from 'react-helmet-async';
 import { Link } from 'react-router-dom';
 import {
@@ -182,6 +183,12 @@ const TRANSLATIONS: Record<Lang, Record<string, string>> = {
     btnPro: 'Pro',
     btnUser: 'User',
     btnAdmin: 'Admin',
+    // Errors
+    loadError: 'Failed to load dashboard data.',
+    loginError: 'Unable to sign in.',
+    updatePlanError: 'Unable to update plan.',
+    updateRoleError: 'Unable to update role.',
+    updateContactError: 'Unable to update contact message.',
   },
   ar: {
     // Page & header
@@ -317,6 +324,12 @@ const TRANSLATIONS: Record<Lang, Record<string, string>> = {
     btnPro: 'Pro',
     btnUser: 'مستخدم',
     btnAdmin: 'مشرف',
+    // Errors
+    loadError: 'فشل تحميل بيانات لوحة التحكم.',
+    loginError: 'تعذّر تسجيل الدخول.',
+    updatePlanError: 'تعذّر تحديث الخطة.',
+    updateRoleError: 'تعذّر تحديث الدور.',
+    updateContactError: 'تعذّر تحديث رسالة التواصل.',
   },
 };
 
@@ -475,7 +488,9 @@ export default function InternalAdminPage() {
         }
       }
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Failed to load dashboard data.');
+      const msg = e instanceof Error ? e.message : t('loadError');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setLoading(false);
     }
@@ -492,7 +507,9 @@ export default function InternalAdminPage() {
       }
       setPassword('');
     } catch (e) {
-      setLoginError(e instanceof Error ? e.message : 'Unable to sign in.');
+      const msg = e instanceof Error ? e.message : t('loginError');
+      setLoginError(msg);
+      toast.error(msg);
     }
   }
 
@@ -504,7 +521,9 @@ export default function InternalAdminPage() {
       await updateInternalAdminUserPlan(userId, plan);
       await loadTab('users');
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Unable to update plan.');
+      const msg = e instanceof Error ? e.message : t('updatePlanError');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setUpdatingUserId(null);
     }
@@ -518,7 +537,9 @@ export default function InternalAdminPage() {
       await updateInternalAdminUserRole(userId, role);
       await loadTab('users');
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Unable to update role.');
+      const msg = e instanceof Error ? e.message : t('updateRoleError');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setUpdatingRoleUserId(null);
     }
@@ -532,7 +553,9 @@ export default function InternalAdminPage() {
       await markInternalAdminContactRead(messageId);
       await loadTab('contacts');
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Unable to update contact message.');
+      const msg = e instanceof Error ? e.message : t('updateContactError');
+      setError(msg);
+      toast.error(msg);
     } finally {
       setMarkingMessageId(null);
     }