P5 wave 1: extract rotatingMachine concerns into focused modules

src/curves/         loader + normalizer (with cross-pressure anomaly
                      detection) + reverseCurve helper
  src/prediction/     predictors (predictFlow/Power/Ctrl) +
                      groupPredictors (lazy group-scope views) +
                      OperatingPoint (pressure-driven prediction setpoints)
  src/drift/          DriftAssessor (per-metric drift) + PredictionHealth
                      (composes flow/power/pressure into HealthStatus +
                      confidence sibling — see OPEN_QUESTIONS 2026-05-10)
  src/pressure/       VirtualPressureChildren (dashboard-sim) +
                      PressureInitialization (real-vs-virtual tracking) +
                      PressureRouter (dispatches by position)
  src/state/          stateBindings (state.emitter listener helper) +
                      isOperationalState
  src/measurement/    measurementHandlers (dispatcher for flow/power/temp/pressure)
  src/flow/           flowController (handleInput body — execSequence,
                      execMovement, flowMovement, emergencystop)
  src/display/        workingCurves (showWorkingCurves + showCoG admin)
  src/commands/       canonical names: set.mode, cmd.startup/shutdown/estop,
                      set.setpoint, set.flow-setpoint,
                      data.simulate-measurement, query.curves, query.cog,
                      child.register. execSequence demuxes by payload.action
                      to canonical cmd.* handlers.
  CONTRACT.md         inputs/outputs/events/children surface

110 basic tests pass (100 new + 10 pre-existing).
specificClass.js / nodeClass.js untouched — integration in P5 wave 2.

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

src/drift/driftAssessor.js

@@ -0,0 +1,135 @@
+'use strict';
+
+/**
+ * DriftAssessor — extracted from rotatingMachine specificClass.
+ *
+ * Wraps the generalFunctions errorMetrics into a per-metric drift
+ * pipeline (flow / power). Holds the latest drift objects so
+ * predictionHealth can reuse them; the host node still mirrors them
+ * onto its own fields for output compatibility.
+ */
+
+class DriftAssessor {
+  /**
+   * @param {object} ctx
+   *   - errorMetrics: assessPoint(metricId, predicted, measured, opts) + assessDrift(...)
+   *   - measurements: MeasurementContainer (for assessDrift history pulls)
+   *   - driftProfiles: { flow, power, ... }
+   *   - resolveProcessRange(metricId, predicted, measured) -> { processMin, processMax }
+   *   - measurementPositionForMetric(metricId) -> string
+   *   - logger: { warn, debug, ... }
+   */
+  constructor(ctx = {}) {
+    this.errorMetrics = ctx.errorMetrics;
+    this.measurements = ctx.measurements;
+    this.driftProfiles = ctx.driftProfiles || {};
+    this.resolveProcessRange = ctx.resolveProcessRange;
+    this.measurementPositionForMetric = ctx.measurementPositionForMetric;
+    this.logger = ctx.logger || { warn() {}, debug() {} };
+    this.latest = { flow: null, power: null };
+  }
+
+  /**
+   * Compute drift for a metric given a freshly-arrived measured value.
+   * Returns the drift object (or null on error / non-finite inputs).
+   */
+  updateMetricDrift(metricId, measuredValue, context = {}) {
+    const position = this._positionForMetric(metricId);
+    const predictedValue = this._getPredicted(metricId, position);
+    const measured = Number(measuredValue);
+    if (!Number.isFinite(predictedValue) || !Number.isFinite(measured)) return null;
+
+    const { processMin, processMax } = this._processRange(metricId, predictedValue, measured);
+    const timestamp = Number(context.timestamp || Date.now());
+    const profile = this.driftProfiles[metricId] || {};
+
+    try {
+      const drift = this.errorMetrics.assessPoint(metricId, predictedValue, measured, {
+        ...profile,
+        processMin,
+        processMax,
+        predictedTimestamp: timestamp,
+        measuredTimestamp: timestamp,
+      });
+      if (drift && drift.valid) this.latest[metricId] = drift;
+      return drift;
+    } catch (err) {
+      this.logger.warn(`Drift update failed for metric '${metricId}': ${err.message}`);
+      return null;
+    }
+  }
+
+  /**
+   * Pull stored predicted/measured series and run a full drift assessment.
+   */
+  assessDrift(measurement, processMin, processMax) {
+    const metricId = String(measurement || '').toLowerCase();
+    const position = this._positionForMetric(metricId);
+    const predicted = this.measurements
+      ?.type(metricId).variant('predicted').position(position).getAllValues();
+    const measured = this.measurements
+      ?.type(metricId).variant('measured').position(position).getAllValues();
+    if (!predicted?.values || !measured?.values) return null;
+
+    return this.errorMetrics.assessDrift(
+      predicted.values,
+      measured.values,
+      processMin,
+      processMax,
+      {
+        metricId,
+        predictedTimestamps: predicted.timestamps,
+        measuredTimestamps: measured.timestamps,
+        ...(this.driftProfiles[metricId] || {}),
+      },
+    );
+  }
+
+  /**
+   * Pure helper: reduce a confidence figure by drift severity and push
+   * matching flag strings. Returns the updated confidence.
+   */
+  applyDriftPenalty(drift, confidence, flags, prefix) {
+    if (!drift || !drift.valid || !Number.isFinite(drift.nrmse)) return confidence;
+    if (drift.immediateLevel >= 3) {
+      confidence -= 0.3;
+      flags.push(`${prefix}_high_immediate_drift`);
+    } else if (drift.immediateLevel === 2) {
+      confidence -= 0.2;
+      flags.push(`${prefix}_medium_immediate_drift`);
+    } else if (drift.immediateLevel === 1) {
+      confidence -= 0.1;
+      flags.push(`${prefix}_low_immediate_drift`);
+    }
+    if (drift.longTermLevel >= 2) {
+      confidence -= 0.1;
+      flags.push(`${prefix}_long_term_drift`);
+    }
+    return confidence;
+  }
+
+  _positionForMetric(metricId) {
+    if (typeof this.measurementPositionForMetric === 'function') {
+      return this.measurementPositionForMetric(metricId);
+    }
+    return metricId === 'flow' ? 'downstream' : 'atEquipment';
+  }
+
+  _processRange(metricId, predicted, measured) {
+    if (typeof this.resolveProcessRange === 'function') {
+      return this.resolveProcessRange(metricId, predicted, measured);
+    }
+    const lo = Math.min(predicted, measured);
+    const hi = Math.max(predicted, measured);
+    return { processMin: lo, processMax: hi > lo ? hi : lo + 1 };
+  }
+
+  _getPredicted(metricId, position) {
+    return Number(
+      this.measurements
+        ?.type(metricId).variant('predicted').position(position).getCurrentValue(),
+    );
+  }
+}
+
+module.exports = DriftAssessor;