fix repeatable migrations

db/routines/R__024_fn_inverter_modbus_caps_patch.sql

@@ -0,0 +1,69 @@
+create or replace function ems.fn_inverter_modbus_caps_patch(
+  p_site_id int,
+  p_inverter_id int,
+  p_patch jsonb
+)
+returns jsonb
+language plpgsql
+as $fn$
+declare
+  v_charge int;
+  v_discharge int;
+  r record;
+begin
+  if not (p_patch ? 'deye_register_max_charge_a')
+     and not (p_patch ? 'deye_register_max_discharge_a') then
+    return jsonb_build_object('ok', false, 'error', 'no_fields');
+  end if;
+
+  v_charge := case
+    when p_patch ? 'deye_register_max_charge_a' then
+      case
+        when p_patch->'deye_register_max_charge_a' is null
+          or jsonb_typeof(p_patch->'deye_register_max_charge_a') = 'null' then null
+        else (p_patch->>'deye_register_max_charge_a')::int
+      end
+    else null
+  end;
+
+  v_discharge := case
+    when p_patch ? 'deye_register_max_discharge_a' then
+      case
+        when p_patch->'deye_register_max_discharge_a' is null
+          or jsonb_typeof(p_patch->'deye_register_max_discharge_a') = 'null' then null
+        else (p_patch->>'deye_register_max_discharge_a')::int
+      end
+    else null
+  end;
+
+  update ems.asset_inverter ai
+  set
+    deye_register_max_charge_a = case
+      when p_patch ? 'deye_register_max_charge_a' then v_charge
+      else ai.deye_register_max_charge_a
+    end,
+    deye_register_max_discharge_a = case
+      when p_patch ? 'deye_register_max_discharge_a' then v_discharge
+      else ai.deye_register_max_discharge_a
+    end
+  where ai.id = p_inverter_id
+    and ai.site_id = p_site_id
+  returning ai.id, ai.code, ai.deye_register_max_charge_a, ai.deye_register_max_discharge_a
+  into r;
+
+  if r.id is null then
+    return jsonb_build_object('ok', false, 'error', 'not_found');
+  end if;
+
+  return jsonb_build_object(
+    'ok', true,
+    'inverter_id', r.id,
+    'code', r.code,
+    'deye_register_max_charge_a', r.deye_register_max_charge_a,
+    'deye_register_max_discharge_a', r.deye_register_max_discharge_a
+  );
+end;
+$fn$;
+
+comment on function ems.fn_inverter_modbus_caps_patch(int, int, jsonb) is
+  'PATCH stropů proudu reg 108/109 – explicitní JSON null maže strop.';