feat: reveal sandbox sub-options only when sandboxing is on

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_tui.py

@@ -1869,3 +1869,29 @@ async def test_poll_sessions_dispatches_due_prompts_and_notifies():
 
         mock_service.dispatch_due_prompts.assert_awaited_once()
         assert any("Prompt sent" in call[0] for call in notify_calls)
+
+
+@pytest.mark.asyncio
+async def test_sandbox_options_hidden_until_switch_on():
+    """The fs/net rows are sub-options of the sandbox switch: hidden until it is
+    turned on, shown when on, hidden again when turned back off."""
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.tui.screens.new_session import NewSessionScreen
+        from textual.widgets import Switch
+
+        app.push_screen(
+            NewSessionScreen(["claude"], is_git_repo=True, sandbox_available=True)
+        )
+        await pilot.pause()
+        options = app.screen.query_one("#sandbox-options")
+        assert options.display is False
+
+        switch = app.screen.query_one("#sandbox-switch", Switch)
+        switch.value = True
+        await pilot.pause()
+        assert options.display is True
+
+        switch.value = False
+        await pilot.pause()
+        assert options.display is False