commander: ensure health report is always sent out before failsafe notificaation

As the failsafe message can reference the health report, the health report
needs to be sent out first. This is generally the case, except there is a
rate limiter set to 2 seconds. So if the report changes quickly, it is
sent out delayed (potentially after the failsafe report).

src/modules/commander/Commander.cpp

@@ -716,6 +716,8 @@ Commander::Commander() :
 	}
 
 	updateParameters();
+
+	_failsafe.setOnNotifyUserCallback(&Commander::onFailsafeNotifyUserTrampoline, this);
 }
 
 Commander::~Commander()
@@ -3000,6 +3002,20 @@ void Commander::send_parachute_command()
 	set_tune_override(tune_control_s::TUNE_ID_PARACHUTE_RELEASE);
 }
 
+void Commander::onFailsafeNotifyUserTrampoline(void *arg)
+{
+	Commander *commander = static_cast<Commander *>(arg);
+	commander->onFailsafeNotifyUser();
+}
+
+void Commander::onFailsafeNotifyUser()
+{
+	// If we are about to inform about a failsafe, we need to ensure any pending health report is sent out first,
+	// as the failsafe message might reference that. This is only needed in case the report is currently rate-limited,
+	// i.e. it had a recent previous change already.
+	_health_and_arming_checks.reportIfUnreportedDifferences();
+}
+
 int Commander::print_usage(const char *reason)
 {
 	if (reason) {