Implement proactive forecast-driven car charging strategy

- Replace reactive export-threshold wallbox activation with proactive
  logic: WallboxA/B activate when forecast ≥ mid AND PV ≥ threshold
  AND SOC ≥ 35%, without requiring grid export surplus
- Add WallboxB no-car detection via grid-delta probe (no PM available):
  after probe window, if grid shift < GridDeltaThreshW → no car, retry
  after configured timeout
- Add EOD soft stop: after 16:00, stop proactive car charging if
  remaining PV estimate can't cover battery deficit to 90% by sunset
- WW boost no longer requires export threshold; dynamic setpoint uses
  tank top temp + hysteresis + boost delta, capped at 60°C
- Proactive wallboxes bypass import-hysteresis shutdown; SOC emergency
  brake uses SOCFloor (5%) instead of standard AllConsumers gate
- Add WWTopTempC to SystemState (ww_top_temp metric from DHW cylinder)
- Add BatteryConfig (capacity_kwh), CarChargingConfig to config
- Add WWMaxSetpointC, WWHysteresisC to StrategicConfig
- Update Decide() signature: forecastKWh + sunsetTime parameters
- Update all tests; add proactive charging test cases

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

configs/ems-config.yaml

@@ -15,6 +15,7 @@ prometheus:
     phase_l1_power: "pcc_ac_active_power_phaseOne"             # per-phase grid power L1 (W)
     phase_l2_power: "pcc_ac_active_power_phaseTwo"             # per-phase grid power L2 (W)
     phase_l3_power: "pcc_ac_active_power_phaseThree"           # per-phase grid power L3 (W)
+    ww_top_temp: "heating_dhw_sensors_temperature_dhwCylinder_top_value"  # DHW cylinder top temperature (°C)
 
 # Shelly actuators
 shelly:
@@ -69,6 +70,8 @@ strategic:
   forecast_high_kwh: 25
   forecast_mid_kwh: 15
   ww_base_c: 48                  # normal WW setpoint (°C)
+  ww_max_setpoint_c: 60          # absolute maximum WW setpoint (°C)
+  ww_hysteresis_c: 5             # Viessmann switchOn = setpoint - hysteresis (°C)
   ww_boost_high_c: 5             # +5°C on high-forecast days (>25 kWh)
   ww_boost_mid_c: 3              # +3°C on medium-forecast days (>15 kWh)
   ww_window_start: "12:30"       # WW boost only allowed from 12:30
@@ -118,6 +121,21 @@ ems:
   trip_goal_file: "/var/lib/ems/trip-goal.json"     # persisted active trip goal
   session_log_file: "/var/lib/ems/sessions.jsonl"   # JSONL log of completed charge sessions
 
+# Battery physical properties (for EOD soft-stop calculation)
+battery:
+  capacity_kwh: 8.0              # usable battery capacity (kWh)
+
+# Proactive car charging strategy (forecast-driven, no export threshold required)
+car_charging:
+  min_soc: 35                    # start car charging only if battery SOC ≥ this (%)
+  soc_floor: 5                   # emergency brake floor — stop if SOC drops below this (%)
+  eod_soc_target: 90             # desired battery SOC at end of day / sunset (%)
+  eod_time: "16:00"              # start EOD soft-stop checks after this time
+  no_car_retry_min: 30           # minutes before retrying after no-car detection
+  pv_threshold_a_w: 1000         # min PV production to start WallboxA (W) — 50% of 2kW rated
+  pv_threshold_b_w: 2000         # min PV production to start WallboxB (W) — 50% of 4kW rated
+  grid_delta_thresh_w: 2000      # min grid power shift after WallboxB activation = car detected (W)
+
 # Known car profiles for trip mode
 cars:
   mini: