fix(control): let battery charging yield to the EV

.changeset/quiet-ev-fuse-recovery.md

@@ -0,0 +1,5 @@
+---
+"ftw": patch
+---
+
+Let home battery charging yield to the car and resume EV charging once measured fuse headroom is stable, without a fixed five-minute pause. Avoid repeated cuts from the same phase reading and reserve room for commands that have not yet appeared in meter data.

go/cmd/ftw/main.go

@@ -3027,6 +3027,10 @@ func main() {
 			// resume charging.
 			evCurtailHeadroomW := loadpoint.SurplusPotentialW(lpStatesSnapshot)
 			boostEVW, boostReserveSoC := activeBatteryBoostTotals(lpController, lpStatesSnapshot, tickNow)
+			var evFuseDemands []loadpoint.FuseDemand
+			if lpController != nil {
+				evFuseDemands = lpController.FuseDemands()
+			}
 
 			ctrlMu.Lock()
 			ctrl.EVSurplusOnlyReserveW = evReserveW
@@ -3035,6 +3039,7 @@ func main() {
 			ctrl.BatteryBoostEVChargingW = boostEVW
 			ctrl.BatteryBoostReserveSoC = boostReserveSoC
 			ctrl.EVCommandedW = loadpoint.CommandedEVPowerW(lpStatesSnapshot)
+			ctrl.SetEVFuseDemands(evFuseDemands)
 			fuseMaxW := ctrl.SiteFuseAmps * ctrl.SiteFuseVoltage * float64(ctrl.SiteFusePhases)
 			targets := control.ComputeDispatch(tel, ctrl, capsSnap, fuseMaxW)
 			planMissingNow := ctrl.Mode.IsPlannerMode() && ctrl.PlanStale

go/internal/control/dispatch.go

@@ -367,6 +367,10 @@ type State struct {
 	// It reserves site capacity before optional battery charging, even before
 	// an EV ramps up and in modes without an accepted optimizer plan.
 	EVCommandedW float64
+	// evFuseDemands keeps this tick's intent before the fuse clamp so optional
+	// battery charging yields even when the EV cannot start yet.
+	evFuseDemands    []evFuseDemand
+	evFuseDemandsSet bool
 
 	// PI controller (outer, site-level)
 	PI *PIController
@@ -2354,6 +2358,7 @@ func applyDispatchSafetyPipeline(
 	}
 	targets = floorMissingSoCDischarge(targets, store)
 	targets = state.floorFullBatteryCharge(targets)
+	targets = clampEVBatteryHeadroom(targets, store, state, fuseMaxW)
 	republishFuseEVCapAfterFuseDischarge(targets, store, state, fuseMaxW)
 	recordDispatchTargets(targets, state, opts.updatePrevTargets, opts.recordDispatch)
 	return targets