fix repeatable migrations

db/routines/R__028_fn_modbus_written_command_ids.sql

@@ -0,0 +1,20 @@
+create or replace function ems.fn_modbus_written_command_ids(
+  p_site_id int,
+  p_lookback interval
+)
+returns jsonb
+language sql
+stable
+as $fn$
+  select coalesce(
+    jsonb_agg(mc.id order by mc.written_at),
+    '[]'::jsonb
+  )
+  from ems.modbus_command mc
+  where mc.site_id = p_site_id
+    and mc.status = 'written'
+    and mc.written_at >= now() - p_lookback;
+$fn$;
+
+comment on function ems.fn_modbus_written_command_ids(int, interval) is
+  'ID written příkazů k ruční verifikaci (GET control/verify).';