fix infeasable na home-01

backend/services/planning_engine.py

@@ -1311,7 +1311,16 @@ def solve_dispatch(
                 prob += z_export[t] == 0
 
         # Ekonomické guardy: ceny v objective nestačí proti maskám / terminal SoC.
-        ref_buy_horizon = min(float(s.buy_price) for s in slots)
+        # Referenční buy jen z ne-záporných slotů: jinak jeden buy<0 v horizontu označí
+        # téměř všechny sloty jako „drahé“ (gi=0 pro dům) → Infeasible (home-01).
+        non_negative_buys = [
+            float(s.buy_price) for s in slots if float(s.buy_price) >= 0.0
+        ]
+        ref_buy_horizon = (
+            min(non_negative_buys)
+            if non_negative_buys
+            else min(float(s.buy_price) for s in slots)
+        )
         min_spread = float(degradation_cost_effective)
         for t in range(T):
             s = slots[t]
@@ -1339,6 +1348,7 @@ def solve_dispatch(
             skip_pv_store_block = (
                 float(s.pv_b_forecast_w) > 0
                 and not getattr(grid, "block_export_on_negative_sell", False)
+                and sell_t < 0
             )
             if (
                 not allow_pre_neg_pv_export