Duplicate layer ids make one legend toggle hide both layers

• Turning off the stations legend entry also removes the alarms layer, and both return together.
• layerManager.getLayers() returns one entry while the code constructed two.
• Deleting an item from a loop-generated list shifts indices and layers begin reusing stale state.

1. Print every layer id with layerName and visible from layerManager.getLayers().
2. Compare the printed count with the number of layers constructed.
3. Look for generic ids such as 'points', 'layer1' or ids built from array indices.
4. Check whether ids contain timestamps or random numbers.

Give each layer a stable business-prefixed id such as 'station-points', 'alarm-points' or 'district-' + g.code, and toggle visibility through the visible prop instead of rebuilding the layer list.

deck.layerManager.getLayers().forEach(function (l, i) {
  console.log(i, l.id, l.constructor.layerName, l.props.visible);
});
// 0 points ScatterplotLayer true
// 只有一条，但代码创建了两个

var layers = [
  new deck.ScatterplotLayer({
    id: 'station-points',
    data: stations,
    getPosition: function (d) { return [d.lng, d.lat]; },
    getRadius: 6,
    radiusUnits: 'pixels',
    getFillColor: [23, 162, 184]
  }),
  new deck.ScatterplotLayer({
    id: 'alarm-points',
    data: alarms,
    getPosition: function (d) { return [d.lng, d.lat]; },
    getRadius: 9,
    radiusUnits: 'pixels',
    getFillColor: [220, 53, 69],
    pickable: true
  })
];

• Generating a new id on every render forces deck.gl to destroy and recreate all layers, causing flicker, lost picking state and slow memory growth.
• Leaving the old layer instance in place after filtering the array keeps its state and keeps it rendering.