feat: persist settings and enrich conversation context

tests/dashboard/route-filters.test.tsx

@@ -32,10 +32,10 @@ describe('route-friendly filters', () => {
   it('hydrates and writes conversation search and status filters', async () => {
     server.use(http.get('/api/conversations', () => HttpResponse.json([])));
     const user = userEvent.setup();
-    renderRoute('/conversations?q=alice&filter=unread', <ConversationRoute />);
+    renderRoute('/conversations?q=alice&filter=received-images', <ConversationRoute />);
     const search = await screen.findByRole('searchbox', { name: 'Search conversations' });
     expect(search).toHaveValue('alice');
-    expect(screen.getByRole('combobox', { name: 'Filter conversations' })).toHaveValue('unread');
+    expect(screen.getByRole('combobox', { name: 'Filter conversations' })).toHaveValue('received-images');
     await user.clear(search);
     await user.type(search, 'bob');
     expect(screen.getByLabelText('Current URL')).toHaveTextContent('q=bob');