fix: shutdown clears delayedMove so abort+autoPickup can't re-engage pump

When PS commanded turnOffAllMachines, executeSequence's interruptible
abort path triggered transitionToState('operational'), which auto-picked
up the queued delayedMove and re-started the pump. Pump bounced
accelerating ↔ decelerating forever and never reached idle.

Clear state.delayedMove at the top of shutdown/emergencystop sequences
so a user-commanded stop cancels any pending move.

Observed live: in pumpingstation-complete-example the basin drained
past stopLevel and equilibrated at ~0.3 m with one pump stuck at min
flow. With this fix pumps shut down cleanly at stopLevel.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/specificClass.js

@@ -885,13 +885,22 @@ _callMeasurementHandler(measurementType, value, position, context) {
       return;
     }
 
+    // A shutdown/emergency-stop must cancel any pending move. Without this,
+    // the abort path below (returnToOperational=true) lets state.transitionToState
+    // auto-pick up state.delayedMove as soon as it lands in 'operational',
+    // which re-engages the pump on every shutdown attempt — pump bounces
+    // forever between accelerating and decelerating and never reaches idle.
+    const interruptible = new Set(["shutdown", "emergencystop"]);
+    if (interruptible.has(sequenceName)) {
+      this.state.delayedMove = null;
+    }
+
     // Interruptible movement: if a shutdown or emergency-stop is requested
     // while a setpoint move is mid-flight (accelerating/decelerating), abort
     // the move first and wait briefly for the FSM to return to 'operational'.
     // Without this, transitions like accelerating->stopping are rejected by
     // stateManager.isValidTransition, leaving the machine running.
     const currentState = this.state.getCurrentState();
-    const interruptible = new Set(["shutdown", "emergencystop"]);
     if (interruptible.has(sequenceName) &&
         (currentState === "accelerating" || currentState === "decelerating")) {
       this.logger.warn(`Sequence '${sequenceName}' requested during '${currentState}'. Aborting active movement.`);