Refactor status package to use portbase/runtime.

Refactor the status package to use portbase/runtime and
make system status readonly. Also adapts the code base
to the new portbase/notifications package.

status/autopilot.go

@@ -0,0 +1,36 @@
+package status
+
+import "context"
+
+var runAutoPilot = make(chan struct{})
+
+func triggerAutopilot() {
+	select {
+	case runAutoPilot <- struct{}{}:
+	default:
+	}
+}
+
+func autoPilot(ctx context.Context) error {
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-runAutoPilot:
+		}
+
+		selected := SelectedSecurityLevel()
+		mitigation := getHighestMitigationLevel()
+
+		active := SecurityLevelNormal
+		if selected != SecurityLevelOff {
+			active = selected
+		} else if mitigation != SecurityLevelOff {
+			active = mitigation
+		}
+
+		setActiveLevel(active)
+
+		pushSystemStatus()
+	}
+}