Add engagement-only conversation mode

tests/dashboard/subreddits.test.tsx

@@ -500,6 +500,20 @@ describe('subreddits page', () => {
       expect(saved[0][1].conversation.mode).toBe('manual');
     });
 
+    it('applies engagement-only policy without autonomous confirmation', async () => {
+      renderSubreddits();
+      const bar = await select('r4r');
+
+      await userEvent.setup().selectOptions(
+        within(bar).getByRole('combobox', { name: 'Set conversation policy for the selected subreddits' }),
+        'Engagement only',
+      );
+
+      await waitFor(() => expect(saved).toHaveLength(1));
+      expect(screen.queryByText('Confirm risky settings')).not.toBeInTheDocument();
+      expect(saved[0][1].conversation.mode).toBe('engagement');
+    });
+
     it('keeps the hybrid mode valid when bulk-applied to a short turn budget', async () => {
       // r/casualconversation defaults to 3 total / 3 rapport, which the hybrid
       // mode rejects. A bulk change has no form to fix it, so it must normalise.