fix BA a KV nefunkcni vecerni prodej

backend/tests/test_planning_dispatch_milp.py

@@ -1222,7 +1222,7 @@ class NegativeSellPvChargeTests(unittest.TestCase):
             50.0,
             operating_mode="AUTO",
         )
-        self.assertEqual(snap.get("planner_build_tag"), "2026-05-24-neg-sell-v3")
+        self.assertEqual(snap.get("planner_build_tag"), "2026-05-24-evening-export-v4")
         self.assertGreater(
             results[0].battery_setpoint_w,
             5_500,
@@ -1234,6 +1234,64 @@ class NegativeSellPvChargeTests(unittest.TestCase):
             "neg okno má dobít na planner soc_max, ne ~92 %",
         )
 
+    def test_fixed_tariff_evening_export_when_sell_above_buy(self) -> None:
+        """BA81: sell 3,7 > buy 3,088 musí exportovat (acq 3,61 + 0,3 by dříve blokovalo)."""
+        slots = [
+            PlanningSlot(
+                interval_start=datetime(2026, 5, 24, 17, 0, tzinfo=timezone.utc),
+                buy_price=3.088,
+                sell_price=3.75,
+                pv_a_forecast_w=0,
+                pv_b_forecast_w=0,
+                load_baseline_w=400,
+                ev1_connected=False,
+                ev2_connected=False,
+                allow_charge=False,
+                allow_discharge_export=True,
+                charge_acquisition_buy_czk_kwh=3.613,
+            )
+        ]
+        battery = _battery(uc_wh=12_500.0, terminal_soc_value_factor=0.0)
+        battery.max_discharge_power_w = 6_250
+        battery.planner_daytime_charge_target_enabled = False
+        hp = SimpleNamespace(
+            rated_heating_power_w=0,
+            tuv_min_temp_c=45.0,
+            tuv_target_temp_c=55.0,
+        )
+        grid = SimpleNamespace(
+            max_import_power_w=17_000,
+            max_export_power_w=16_000,
+            block_export_on_negative_sell=False,
+        )
+        vehicles = [
+            SimpleNamespace(
+                max_charge_power_w=0,
+                battery_capacity_kwh=1.0,
+                default_target_soc_pct=80.0,
+            ),
+            SimpleNamespace(
+                max_charge_power_w=0,
+                battery_capacity_kwh=1.0,
+                default_target_soc_pct=80.0,
+            ),
+        ]
+        soc0 = 0.95 * battery.usable_capacity_wh
+        results, _ms, _ = solve_dispatch(
+            slots,
+            battery,
+            hp,
+            grid,
+            [None, None],
+            vehicles,
+            soc0,
+            50.0,
+            operating_mode="AUTO",
+        )
+        r0 = results[0]
+        self.assertLess(r0.grid_setpoint_w, 0, "očekáván export do sítě")
+        self.assertEqual(r0.export_mode, "BATTERY_SELL")
+
 
 class AutoPvSurplusExportTests(unittest.TestCase):
     """Plná baterie + vysoká FVE: export přebytku (ge_pv), ne curtailment, bez SELL."""