Use Landlock to restrict bash calls. (#5)

https://docs.kernel.org/userspace-api/landlock.html
Reviewed-on: #5
Co-authored-by: Drew Galbraith <drew@tiramisu.one>
Co-committed-by: Drew Galbraith <drew@tiramisu.one>

src/tui/events.rs

@@ -62,6 +62,9 @@ pub(super) fn drain_ui_events(event_rx: &mut mpsc::Receiver<UIEvent>, state: &mu
             UIEvent::TurnComplete => {
                 debug!("turn complete");
             }
+            UIEvent::NetworkPolicyChanged(allowed) => {
+                state.network_allowed = allowed;
+            }
             UIEvent::Error(msg) => {
                 state
                     .messages