fix: production hardening — safety fixes, prediction accuracy, test coverage

Safety:
- Async input handler: await all handleInput() calls, prevents unhandled rejections
- Fix emergencyStop case mismatch: "emergencyStop" → "emergencystop" matching config
- Implement showCoG() method (was routing to undefined)
- Null guards on 6 methods for missing curve data
- Editor menu polling timeout (5s max)
- Listener cleanup on node close (child measurements + state emitter)
- Tick loop race condition: track startup timeout, clear on close

Prediction accuracy:
- Remove efficiency rounding that destroyed signal in canonical units
- Fix calcEfficiency variant: hydraulic power reads from correct variant
- Guard efficiency calculations against negative/zero values
- Division-by-zero protection in calcRelativeDistanceFromPeak
- Curve data anomaly detection (cross-pressure median-y ratio check)
- calcEfficiencyCurve O(n²) → O(n) with running min
- updateCurve bootstraps predictors when they were null

Tests: 43 new tests (76 total) covering emergency stop, shutdown/maintenance
sequences, efficiency/CoG, movement lifecycle, output format, null guards,
and listener cleanup.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/edge/output-format.edge.test.js

@@ -0,0 +1,121 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const Machine = require('../../src/specificClass');
+const { makeMachineConfig, makeStateConfig } = require('../helpers/factories');
+
+test('getOutput contains all required fields in idle state', () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig());
+
+  const output = machine.getOutput();
+
+  // Core state fields
+  assert.equal(output.state, 'idle');
+  assert.ok('runtime' in output);
+  assert.ok('ctrl' in output);
+  assert.ok('moveTimeleft' in output);
+  assert.ok('mode' in output);
+  assert.ok('maintenanceTime' in output);
+
+  // Efficiency fields
+  assert.ok('cog' in output);
+  assert.ok('NCog' in output);
+  assert.ok('NCogPercent' in output);
+  assert.ok('effDistFromPeak' in output);
+  assert.ok('effRelDistFromPeak' in output);
+
+  // Prediction health fields
+  assert.ok('predictionQuality' in output);
+  assert.ok('predictionConfidence' in output);
+  assert.ok('predictionPressureSource' in output);
+  assert.ok('predictionFlags' in output);
+
+  // Pressure drift fields
+  assert.ok('pressureDriftLevel' in output);
+  assert.ok('pressureDriftSource' in output);
+  assert.ok('pressureDriftFlags' in output);
+});
+
+test('getOutput flow drift fields appear after sufficient measured flow samples', async () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig());
+
+  await machine.handleInput('parent', 'execSequence', 'startup');
+  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
+  await machine.handleInput('parent', 'execMovement', 50);
+
+  // Provide multiple measured flow samples to trigger valid drift assessment
+  const baseTime = Date.now();
+  for (let i = 0; i < 12; i++) {
+    machine.updateMeasuredFlow(100 + i, 'downstream', {
+      timestamp: baseTime + (i * 1000),
+      unit: 'm3/h',
+      childId: 'flow-sensor',
+      childName: 'FT-1',
+    });
+  }
+
+  const output = machine.getOutput();
+
+  // Drift fields should appear once enough samples provide a valid assessment
+  if ('flowNrmse' in output) {
+    assert.ok(typeof output.flowNrmse === 'number');
+    assert.ok('flowDriftValid' in output);
+  }
+  // At minimum, prediction health fields should always be present
+  assert.ok('predictionQuality' in output);
+  assert.ok('predictionConfidence' in output);
+});
+
+test('getOutput prediction confidence is 0 in non-operational state', () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig());
+
+  const output = machine.getOutput();
+
+  assert.equal(output.predictionConfidence, 0);
+});
+
+test('getOutput prediction confidence reflects differential pressure', () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));
+
+  // Differential pressure → high confidence
+  machine.updateMeasuredPressure(800, 'upstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt-up' });
+  machine.updateMeasuredPressure(1200, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt-down' });
+
+  const output = machine.getOutput();
+
+  assert.ok(output.predictionConfidence >= 0.8, `Confidence ${output.predictionConfidence} should be >= 0.8 with differential pressure`);
+  assert.equal(output.predictionPressureSource, 'differential');
+});
+
+test('getOutput values are in configured output units not canonical', () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));
+
+  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
+  machine.updatePosition();
+
+  const output = machine.getOutput();
+
+  // Flow keys should contain values in m3/h (configured), not m3/s (canonical)
+  // Predicted flow at minimum pressure should be in a reasonable m3/h range, not ~0.003 m3/s
+  const flowKey = Object.keys(output).find(k => k.startsWith('flow.predicted.downstream'));
+  if (flowKey) {
+    const flowVal = output[flowKey];
+    assert.ok(typeof flowVal === 'number', 'Flow output should be a number');
+    // m3/h values are typically 0-300, m3/s values are 0-0.08
+    // If in canonical units it would be very small
+    if (flowVal > 0) {
+      assert.ok(flowVal > 0.1, `Flow value ${flowVal} looks like canonical m3/s, should be m3/h`);
+    }
+  }
+});
+
+test('getOutput NCogPercent is correctly derived from NCog', () => {
+  const machine = new Machine(makeMachineConfig(), makeStateConfig({ state: { current: 'operational' } }));
+
+  machine.updateMeasuredPressure(1000, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'pt' });
+  machine.updatePosition();
+
+  const output = machine.getOutput();
+  const expected = Math.round(output.NCog * 100 * 100) / 100;
+  assert.equal(output.NCogPercent, expected, 'NCogPercent should be NCog * 100, rounded to 2 decimals');
+});