Revert: handleInput unchanged-demand short-circuit

Reverts a14aa0d. The "skip when demand unchanged" optimisation broke
the live demo: in some real conditions (basin transitions, safety
controller activations) PS sends repeated demand=0 and the optimisation
correctly turned pumps off the first time but then declined to re-act
when conditions changed in a way the test suite didn't cover. Live
result: pumps stayed off even when basin filled to overflow.

The original symptom (pumps stuck mid-ramp under saturated demand) needs
a different approach — likely a pump-side guard rather than an MGC-side
demand filter. Investigating in a follow-up.

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

src/specificClass.js

@@ -1281,25 +1281,6 @@ class MachineGroup {
             return;
         }
 
-        // Skip abort + redispatch when the demand hasn't changed beyond a
-        // small tolerance. PS ticks every 1 s and re-fires the same demand
-        // while the basin level evolves slowly; without this guard, every
-        // PS tick aborted in-flight pump moves before they could finish
-        // (move duration ~0.4 s, abort cycle 1 s, but each abort
-        // immediately re-issued the same setpoint, so pumps got stuck
-        // ramping from the same starting position to the same target
-        // forever). Tolerance is 0.5 % — small enough that real demand
-        // changes still propagate, big enough to filter PS hysteresis
-        // float jitter.
-        const prev = this._lastDemandQ;
-        const unchanged = Number.isFinite(prev)
-            && Math.abs(demandQ - prev) < Math.max(0.5, Math.abs(prev) * 0.005);
-        if (unchanged) {
-            this.logger.debug(`Demand ${demandQ} unchanged from ${prev}; skipping abort+redispatch`);
-            return;
-        }
-        this._lastDemandQ = demandQ;
-
         //abort current movements
         await this.abortActiveMovements("new demand received");