refactor(units): use UnitPolicy.convert instead of hardcoded m3/h<->m3/s scalars

Replace the M3H_TO_M3S constant in control/manual.js and the `* 3600`
inline conversion in the status badge with this.unitPolicy.convert
calls. Expose unitPolicy on the frozen control context so manual
strategies pick it up without reaching into host. Matches the
contract direction in .claude/refactor/CONTRACTS.md §6.

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

src/specificClass.js

@@ -146,6 +146,7 @@ class PumpingStation extends BaseDomain {
       levelVariants: this.levelVariants,
       volVariants: this.volVariants,
       flowThreshold: this.flowThreshold,
+      unitPolicy: this.unitPolicy,
       host: this,
     };
     Object.defineProperty(ctx, 'machines',      { enumerable: true, get: () => host.machines });
@@ -262,7 +263,7 @@ class PumpingStation extends BaseDomain {
     };
     const { arrow = '❔', fill = 'grey' } = STYLES[this.state?.direction] || {};
     const pct = this.measurements.type('volumePercent').variant('predicted').position('atequipment').getCurrentValue() ?? 0;
-    const netFlowM3h = (this.state?.netFlow ?? 0) * 3600;
+    const netFlowM3h = this.unitPolicy.convert(this.state?.netFlow ?? 0, 'm3/s', 'm3/h', 'status badge netFlow');
     const mode = this.mode || '?';
     const manualPart = this.mode === 'manual' && Number.isFinite(this._manualDemand)
       ? `Qd=${this._manualDemand.toFixed(0)} m³/h` : null;
@@ -289,6 +290,10 @@ class PumpingStation extends BaseDomain {
       this.logger.debug(
         `Measurement update ${eventName} <- ${eventData.childName || child.config.general.name}: ${eventData.value} ${eventData.unit}`
       );
+      if (measurementType === 'level') {
+        this.measurementRouter.route(measurementType, eventData.value, position, eventData);
+        return;
+      }
       this.measurements.type(measurementType).variant('measured').position(position)
         .value(eventData.value, eventData.timestamp, eventData.unit);
       this.measurementRouter.route(measurementType, eventData.value, position, eventData);