fix: translation jumping on auto-translations (#50)

Co-authored-by: hugo <hugoms@me.com>

src/renderer/components/Editor/PostEditor.tsx

@@ -769,7 +769,7 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
     }
   }, [title, content, isDetectingLanguage, tr]);
 
-  const handleTranslatePost = useCallback(async (targetLanguage: string) => {
+  const handleTranslatePost = useCallback(async (targetLanguage: string, options?: { switchToTarget?: boolean }) => {
     if (!targetLanguage || isTranslatingPost) return;
     setIsTranslatingPost(true);
     try {
@@ -782,8 +782,13 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
           updatePost(postId, refreshedPost as Partial<PostData>);
           setPost(prev => prev ? { ...prev, ...refreshedPost as Partial<PostData> } : prev);
         }
+        // Only switch the editing language when the user explicitly requested
+        // it via the quick action modal. Background/auto translations must
+        // never move the editor away from the language the user is working on.
+        if (options?.switchToTarget) {
           const refreshedMap = mapTranslationsByLanguage(loadedTranslations);
           applyDisplayedDraft(targetLanguage, canonicalDraft, refreshedMap);
+        }
         showToast.success(tr('editor.translations.translateSuccess', { language: getLanguageLabel(targetLanguage) }));
       } else {
         showToast.error(result?.error || tr('editor.translations.translateFailed'));
@@ -813,7 +818,7 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
   const handleConfirmTranslation = useCallback(() => {
     if (!translationTargetLanguage) return;
     setShowTranslationModal(false);
-    void handleTranslatePost(translationTargetLanguage);
+    void handleTranslatePost(translationTargetLanguage, { switchToTarget: true });
   }, [handleTranslatePost, translationTargetLanguage]);
 
   // Load project language for AI post analysis

tests/renderer/components/EditorPostAISuggestions.test.tsx

@@ -329,6 +329,58 @@ describe('Editor AI post suggestions', () => {
     expect((window as any).electronAPI.chat.translatePost).toHaveBeenCalledWith('post-1', 'fr');
   });
 
+  it('switches editing language to translated language when confirmed via quick action modal', async () => {
+    const frTranslation = createTranslation({ language: 'fr', title: 'Bonjour le monde', excerpt: 'Resume', content: 'Contenu traduit' });
+    (window as any).electronAPI.posts.get = vi.fn().mockResolvedValue(createPost({
+      title: 'Hello world',
+      language: 'en',
+      content: 'Original content',
+    }));
+    (window as any).electronAPI.posts.requestAutoTranslation = vi.fn().mockResolvedValue(undefined);
+    // First call (initial load) returns empty, subsequent calls return the french translation
+    (window as any).electronAPI.posts.getTranslations = vi.fn()
+      .mockResolvedValueOnce([])
+      .mockResolvedValue([frTranslation]);
+    (window as any).electronAPI.chat.translatePost = vi.fn().mockResolvedValue({ success: true });
+
+    const view = render(<PostEditor postId="post-1" />);
+    const ui = within(view.container);
+
+    // Wait for post data to load and editor to initialize
+    await act(async () => {
+      await Promise.resolve();
+      await Promise.resolve();
+      await Promise.resolve();
+      await Promise.resolve();
+    });
+
+    // Expand metadata section so the title input is visible
+    await act(async () => {
+      fireEvent.click(ui.getByRole('button', { name: /Metadata/i }));
+    });
+
+    // Verify canonical content is shown initially
+    const titleInput = view.container.querySelector('#post-editor-post-1-title') as HTMLInputElement;
+    expect(titleInput?.value).toBe('Hello world');
+
+    // Open quick actions → translate modal
+    await act(async () => { fireEvent.click(ui.getByRole('button', { name: '⚡ Quick Actions' })); });
+    await act(async () => { fireEvent.click(ui.getByRole('button', { name: /Translate to\.\.\./i })); });
+    await act(async () => { fireEvent.change(ui.getByLabelText('Select target language'), { target: { value: 'fr' } }); });
+
+    // Confirm translation from the quick action modal
+    await act(async () => {
+      fireEvent.click(ui.getByRole('button', { name: 'Translate to...' }));
+      await Promise.resolve();
+      await Promise.resolve();
+      await Promise.resolve();
+      await Promise.resolve();
+    });
+
+    // After quick-action translation, editor should switch to the translated content
+    expect(titleInput?.value).toBe('Bonjour le monde');
+  });
+
   it('renders available translations as compact flag indicators in metadata', async () => {
     (window as any).electronAPI.posts.get = vi.fn().mockResolvedValue(createPost({ title: '' }));
     (window as any).electronAPI.posts.getTranslations = vi.fn().mockResolvedValue([