guild scouting improvements

patch-schema/mail-system-messages.sql

@@ -0,0 +1,13 @@
+BEGIN;
+
+ALTER TABLE IF EXISTS public.mail
+    ADD COLUMN IF NOT EXISTS is_sys_message bool DEFAULT false;
+
+UPDATE mail SET is_sys_message=false;
+
+ALTER TABLE IF EXISTS public.mail
+    DROP CONSTRAINT IF EXISTS mail_sender_id_fkey;
+
+INSERT INTO public.characters (id, name) VALUES (0, '');
+
+END;