fix(fires): keep retained heat hidden when reenabling an empty filter

Add a lifecycle regression and register it in the format scope.

docs/CURRENT-STATE.md

@@ -2231,6 +2231,8 @@ view), so the weak fires the heatmap shows stay on screen as markers when it
 fades out; it reads each marker's already-built anchor instead of the ground
 floor cache, which only the close band warms. "N FIRES" cards from a 2° / 1° aggregation still label the hottest
 areas; their accent is the strongest fire's FRP color.
+Re-enabling Active Fires keeps the retained heat imagery hidden when the current
+filtered set is empty, including while a new snapshot is pending.
 
 The Active Fires row carries a "Fire intensity (FRP)" slider on a log scale
 whose track is painted with the ramp and ticked at the same six values (its

scripts/format-scope.json

@@ -408,6 +408,7 @@
   "src/layers/firms/cards.js",
   "src/layers/firms/index.js",
   "src/layers/firms/ingestion.js",
+  "src/layers/firms/heatVisibility.test.mjs",
   "src/layers/firms/lifecycle.js",
   "src/layers/firms/model.js",
   "src/layers/firms/policy.js",

src/layers/firms/heatVisibility.test.mjs

@@ -0,0 +1,44 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createLifecycle } from './lifecycle.js';
+
+test('reenabling an empty filtered layer never reveals the retained pre-filter heat raster', async () => {
+  let shown = false;
+  const noop = () => {};
+  const layerState = {
+    _enabled: false,
+    _viewer: {},
+    _dataSource: {},
+    _fires: [],
+    _loading: true,
+    _pickIndexById: new Map(),
+    _heatImagery: {
+      setShow(v) {
+        shown = v;
+      },
+    },
+  };
+  const lifecycle = createLifecycle({
+    layerState,
+    services: {
+      picking: { registerPickOwner: noop, unregisterPickOwner: noop },
+      sprites: { restoreSpriteOrderOnEnable: noop },
+      context: { clearSelectedEntityContextForLayer: noop },
+    },
+    config: { id: 'local-firms', overlayHost: { setVisible: noop } },
+    components: {
+      rendering: { applyHandoffFade: noop },
+      viewport: { installLodWatcher: noop, installMoveEndWatcher: noop },
+      selection: { installClickHandler: noop },
+    },
+  });
+  await lifecycle.methods.enable(layerState._viewer);
+  assert.equal(
+    shown,
+    false,
+    'empty current set must keep the old raster hidden while refresh is pending',
+  );
+  layerState._fires = [{ frp: null, confidence: null }];
+  await lifecycle.methods.enable(layerState._viewer);
+  assert.equal(shown, true, 'nonempty sets still resume their raster');
+});

src/layers/firms/lifecycle.js

@@ -54,7 +54,8 @@ export function createLifecycle({
         layerState._billboards.show = true;
       }
       overlayHost.setVisible(FIRMS_OVERLAY_SOURCE_ID, true);
-      layerState._heatImagery?.setShow(true);
+      // A filter can leave an old raster cached while the current set is empty.
+      layerState._heatImagery?.setShow(layerState._fires.length > 0);
       // The camera can have crossed the hand-off while the layer was off.
       components.rendering.applyHandoffFade(true);
       components.viewport.installLodWatcher();