Remember last used channel when selected

frontend/src/test/appStartupHash.test.tsx

@@ -137,6 +137,10 @@ vi.mock('../components/ui/sonner', () => ({
 }));
 
 import { App } from '../App';
+import {
+  LAST_VIEWED_CONVERSATION_KEY,
+  REOPEN_LAST_CONVERSATION_KEY,
+} from '../utils/lastViewedConversation';
 
 const publicChannel = {
   key: '8B3387E9C5CDEA6AC9E5EDBAA115CD72',
@@ -149,6 +153,7 @@ const publicChannel = {
 describe('App startup hash resolution', () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    localStorage.clear();
     window.location.hash = `#contact/${'a'.repeat(64)}/Alice`;
 
     mocks.api.getRadioConfig.mockResolvedValue({
@@ -178,6 +183,7 @@ describe('App startup hash resolution', () => {
 
   afterEach(() => {
     window.location.hash = '';
+    localStorage.clear();
   });
 
   it('falls back to Public when contact hash is unresolvable and contacts are empty', async () => {
@@ -189,4 +195,63 @@ describe('App startup hash resolution', () => {
       }
     });
   });
+
+  it('restores last viewed channel when hash is empty and reopen preference is enabled', async () => {
+    const chatChannel = {
+      key: '11111111111111111111111111111111',
+      name: 'Ops',
+      is_hashtag: false,
+      on_radio: false,
+      last_read_at: null,
+    };
+
+    window.location.hash = '';
+    localStorage.setItem(REOPEN_LAST_CONVERSATION_KEY, '1');
+    localStorage.setItem(
+      LAST_VIEWED_CONVERSATION_KEY,
+      JSON.stringify({
+        type: 'channel',
+        id: chatChannel.key,
+        name: chatChannel.name,
+      })
+    );
+    mocks.api.getChannels.mockResolvedValue([publicChannel, chatChannel]);
+
+    render(<App />);
+
+    await waitFor(() => {
+      for (const node of screen.getAllByTestId('active-conversation')) {
+        expect(node).toHaveTextContent(`channel:${chatChannel.key}:${chatChannel.name}`);
+      }
+    });
+  });
+
+  it('uses Public channel when hash is empty and reopen preference is disabled', async () => {
+    const chatChannel = {
+      key: '11111111111111111111111111111111',
+      name: 'Ops',
+      is_hashtag: false,
+      on_radio: false,
+      last_read_at: null,
+    };
+
+    window.location.hash = '';
+    localStorage.setItem(
+      LAST_VIEWED_CONVERSATION_KEY,
+      JSON.stringify({
+        type: 'channel',
+        id: chatChannel.key,
+        name: chatChannel.name,
+      })
+    );
+    mocks.api.getChannels.mockResolvedValue([publicChannel, chatChannel]);
+
+    render(<App />);
+
+    await waitFor(() => {
+      for (const node of screen.getAllByTestId('active-conversation')) {
+        expect(node).toHaveTextContent(`channel:${publicChannel.key}:Public`);
+      }
+    });
+  });
 });

frontend/src/test/settingsModal.test.tsx

@@ -11,6 +11,10 @@ import type {
   StatisticsResponse,
 } from '../types';
 import type { SettingsSection } from '../components/SettingsModal';
+import {
+  LAST_VIEWED_CONVERSATION_KEY,
+  REOPEN_LAST_CONVERSATION_KEY,
+} from '../utils/lastViewedConversation';
 
 const baseConfig: RadioConfig = {
   public_key: 'aa'.repeat(32),
@@ -128,9 +132,16 @@ function openConnectivitySection() {
   fireEvent.click(connectivityToggle);
 }
 
+function openDatabaseSection() {
+  const databaseToggle = screen.getByRole('button', { name: /Database/i });
+  fireEvent.click(databaseToggle);
+}
+
 describe('SettingsModal', () => {
   afterEach(() => {
     vi.restoreAllMocks();
+    localStorage.clear();
+    window.location.hash = '';
   });
 
   it('refreshes app settings when opened', async () => {
@@ -291,6 +302,25 @@ describe('SettingsModal', () => {
     expect(onClose).not.toHaveBeenCalled();
   });
 
+  it('stores and clears reopen-last-conversation preference locally', () => {
+    window.location.hash = '#raw';
+    renderModal();
+    openDatabaseSection();
+
+    const checkbox = screen.getByLabelText('Reopen to last viewed channel/conversation');
+    expect(checkbox).not.toBeChecked();
+
+    fireEvent.click(checkbox);
+
+    expect(localStorage.getItem(REOPEN_LAST_CONVERSATION_KEY)).toBe('1');
+    expect(localStorage.getItem(LAST_VIEWED_CONVERSATION_KEY)).toContain('"type":"raw"');
+
+    fireEvent.click(checkbox);
+
+    expect(localStorage.getItem(REOPEN_LAST_CONVERSATION_KEY)).toBeNull();
+    expect(localStorage.getItem(LAST_VIEWED_CONVERSATION_KEY)).toBeNull();
+  });
+
   it('renders statistics section with fetched data', async () => {
     const mockStats: StatisticsResponse = {
       busiest_channels_24h: [