fix(outlines): harden shared cache and provider lifecycle

src/standalone/layerSources.js

@@ -21,8 +21,13 @@ import { createReferenceSources } from '../sources/reference.js';
 export { createReferenceSources as createStandaloneReferenceSources } from '../sources/reference.js';
 
 /** Select standalone providers without starting their acquisition. */
-export function createStandaloneLayerSources() {
-  const mapTiles = createOpenFreeMapSource();
+export function createStandaloneLayerSources({
+  createMapTiles = createOpenFreeMapSource,
+} = {}) {
+  // Each subsystem owns its own request lifetime and local result cache. The
+  // sources still share the bounded decoded-tile owner inside OpenFreeMap.
+  const trafficTiles = createMapTiles();
+  const installationTiles = createMapTiles();
   return {
     ...createReferenceSources(),
     flights: createOpenSkySource(),
@@ -32,10 +37,10 @@ export function createStandaloneLayerSources() {
     }),
     cctv: createCctvSource(),
     radio: createRadioSource(),
-    traffic: createTrafficSource({ mapTiles }),
+    traffic: createTrafficSource({ mapTiles: trafficTiles }),
     transit: createTransitSource(),
     bikeshare: createBikeshareSource(),
-    installations: createInstallationSource({ mapTiles }),
+    installations: createInstallationSource({ mapTiles: installationTiles }),
     satellites: createSatelliteSource(),
     launches: createLaunchSource(),
     alpr: createAlprTileSource(),

src/standalone/layerSources.test.mjs

@@ -0,0 +1,38 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createStandaloneLayerSources } from './layerSources.js';
+
+test('traffic and installations own separate local OpenFreeMap lifetimes', () => {
+  const mapTiles = [];
+  const sources = createStandaloneLayerSources({
+    createMapTiles() {
+      const source = {
+        clears: 0,
+        clear() {
+          this.clears++;
+        },
+        getMetadata: async () => ({
+          template: 'https://tiles.openfreemap.org/planet/test/{z}/{x}/{y}.pbf',
+        }),
+        fetchBounds: async () => ({ tiles: [], loadedTiles: [] }),
+      };
+      mapTiles.push(source);
+      return source;
+    },
+  });
+
+  assert.equal(mapTiles.length, 2);
+  assert.notEqual(mapTiles[0], mapTiles[1]);
+  sources.traffic.resetFlowTileCache();
+  assert.deepEqual(
+    mapTiles.map((source) => source.clears),
+    [1, 0],
+    'traffic reset cannot clear installation work',
+  );
+  sources.installations.destroy();
+  assert.deepEqual(
+    mapTiles.map((source) => source.clears),
+    [1, 1],
+    'installation destroy cannot clear traffic work',
+  );
+});