dalsi fix - chtel drzet baterii prakticky porad a neprodat ani nejeet passive mode

db/routines/R__063_fn_load_planning_slots_full.sql

@@ -61,6 +61,7 @@ declare
   v_daytime_en boolean;
   v_night_buf_pct numeric;
   v_degrad_czk_kwh numeric;
+  v_ref_buy_czk_kwh numeric;
 begin
   drop table if exists _ems_plan_slot_wk;
   create temp table _ems_plan_slot_wk on commit drop as
@@ -323,6 +324,17 @@ begin
     end loop;
   end if;
 
+  -- Referenční nákup pro arbitráž exportu: nejlevnější buy mezi sloty, kde lze nabíjet
+  -- (ne buy ve stejném slotu — střídač nekupuje a neprodává současně).
+  select coalesce(
+    min(wk.buy_price) filter (where wk.allow_charge),
+    min(wk.buy_price)
+  )
+  into v_ref_buy_czk_kwh
+  from _ems_plan_slot_wk wk;
+
+  v_ref_buy_czk_kwh := coalesce(v_ref_buy_czk_kwh, 0);
+
   -- discharge-export mask
   if v_discharge_buf <= 0 then
     update _ems_plan_slot_wk wk set allow_discharge_export = true;
@@ -334,7 +346,7 @@ begin
     for r_slot in
       select wk.slot_ord
       from _ems_plan_slot_wk wk
-      where wk.sell_price > wk.buy_price + v_degrad_czk_kwh
+      where wk.sell_price > v_ref_buy_czk_kwh + v_degrad_czk_kwh
       order by wk.sell_price desc, wk.slot_ord desc
     loop
       exit when v_cum >= v_discharge_target_wh;