fix(satellites): class choices survive a reload and travel in share links

Only catalog and the tracked satellite were saved for the layer, so a class
chip lasted until the next reload and no share link carried it. The choice
is now the satellites option `classes`: one letter per class shown
(`sitpd` by default, `0` for none), with Starlink left to `catalog`, and
the layer takes the letters back through setParams. A partial request
(`{debris: false}`) hides only what it names.

src/data/layerState.js

@@ -2,6 +2,7 @@
 // Local, not i18n/marker.js: the token-ledger tests run this file in isolation.
 const msg = (text) => text;
 import { normalizeIdSwitches, patchRequestedIdSwitches } from './idSwitches.js';
+import { normalizeSatelliteClassMask } from './satelliteClassMask.js';
 import reservationRows from './layerStateTokenReservations.json' with { type: 'json' };
 
 const VALID_DISPOSITIONS = new Set([
@@ -416,6 +417,16 @@ const OPTION_GROUPS = Object.freeze({
       dense: 'd',
     }),
     integerOption('selectedSatTrackingId', 't', null),
+    // Every class but Starlink shows by default (satellites/classes.js).
+    Object.freeze({
+      key: 'classes',
+      token: 'k',
+      defaultValue: 'sitpd',
+      normalize: normalizeSatelliteClassMask,
+      encode: (value) => value,
+      decode: (value) =>
+        typeof value === 'string' ? normalizeSatelliteClassMask(value) : null,
+    }),
   ]),
   cctv: Object.freeze([
     enumOption('coverageMode', 'c', 'on', ['off', 'on', 'viewshed'], {

src/data/layerState.test.mjs

@@ -970,6 +970,41 @@ test('a direct Context selection promotes its owned tracker layer before persist
   coordinator.destroy();
 });
 
+test('a satellite class choice is saved, shared and restored', async () => {
+  const storage = memoryStorage();
+  const manager = productionManager();
+  const coordinator = new LayerStateCoordinator(manager, shareSink(), {
+    storage,
+  });
+  await coordinator.start();
+  await manager.setEnabled('satellites', true, { origin: 'user' });
+  assert.equal(
+    coordinator.getDurableState().options.satellites.classes,
+    'sitpd',
+    'every class but Starlink by default',
+  );
+  manager.setLayerParams(
+    'satellites',
+    { classes: { debris: false } },
+    { origin: 'user' },
+  );
+  const durable = coordinator.getDurableState();
+  assert.equal(durable.options.satellites.classes, 'sitp');
+  assert.equal(
+    new URLSearchParams(encode(durable)).get('lo')?.includes('s.k.sitp'),
+    true,
+  );
+  coordinator.destroy();
+
+  // A reload hands the layer its letters back (the layer decodes them:
+  // src/data/satelliteClass.test.mjs).
+  const reloaded = productionManager();
+  const next = new LayerStateCoordinator(reloaded, shareSink(), { storage });
+  await next.start();
+  assert.equal(reloaded.getLayerParams('satellites')?.classes, 'sitp');
+  next.destroy();
+});
+
 test('explicit Flight to Satellite replacement keeps the new Satellite ID durable', async () => {
   const manager = productionManager();
   const coordinator = new LayerStateCoordinator(manager, shareSink(), {

src/data/layerStateTokenLedger.test.mjs

@@ -102,12 +102,13 @@ const preWildlifeRows = reservationRows.filter(
 );
 
 function writeCodecFixture(cwd, rows, entries) {
-  const providerCodec = path.join(cwd, 'src/data/idSwitches.js');
-  mkdirSync(path.dirname(providerCodec), { recursive: true });
-  writeFileSync(
-    providerCodec,
-    readFileSync(new URL('./idSwitches.js', import.meta.url)),
-  );
+  mkdirSync(path.join(cwd, 'src/data'), { recursive: true });
+  // The codec's own imports, beside it.
+  for (const name of ['idSwitches.js', 'satelliteClassMask.js'])
+    writeFileSync(
+      path.join(cwd, 'src/data', name),
+      readFileSync(new URL(`./${name}`, import.meta.url)),
+    );
   let source = readFileSync(CODEC_SOURCE_PATH, 'utf8');
   if (!rows.some(([id]) => id === 'wildlife-sightings'))
     source = source.replace(

src/data/satelliteClass.test.mjs

@@ -469,6 +469,18 @@ test('every class but Starlink shows by default; each class chip turns its class
     satellitesLayer.setParams(chip('imaging').params);
     assert.deepEqual(shown(), [25544, 40001], 'telecom back on, imaging off');
     assert.equal(satellitesLayer.setParams({ classes: 'all' }), false, 'malformed request refused');
+
+    // A saved or shared choice comes back as class letters.
+    assert.equal(satellitesLayer.setParams({ classes: 'sip' }), true);
+    assert.deepEqual(satellitesLayer.getParams().classes, {
+      stations: true,
+      imaging: true,
+      telecom: false,
+      starlink: false,
+      probes: true,
+      debris: false,
+    });
+    assert.deepEqual(shown(), [25544, 40002], 'restored from letters');
   } finally {
     console.log = log;
     console.warn = warn;

src/data/satelliteClassMask.js

@@ -0,0 +1,54 @@
+/**
+ * @file The satellites layer's class choice as share-link and saved-state
+ * letters. Shared by the layer-state codec and the layer, which takes a saved
+ * choice back in this form.
+ */
+
+/**
+ * Satellite classes shown, as one letter each in legend order: stations,
+ * imaging, telecom, probes, debris (`sitpd`, every one; `0`, none).
+ * Starlink is the `catalog` option's, so it has no letter here.
+ */
+const SATELLITE_CLASS_LETTERS = Object.freeze([
+  ['stations', 's'],
+  ['imaging', 'i'],
+  ['telecom', 't'],
+  ['probes', 'p'],
+  ['debris', 'd'],
+]);
+const SATELLITE_CLASS_MASK = /^(0|s?i?t?p?d?)$/;
+
+/**
+ * The canonical class letters for a class choice (an object of booleans, as
+ * the layer's `classes` param, or a partial one) or for letters already,
+ * else null.
+ * @param {unknown} value
+ * @returns {string|null}
+ */
+export function normalizeSatelliteClassMask(value) {
+  if (typeof value === 'string')
+    return value && SATELLITE_CLASS_MASK.test(value) ? value : null;
+  if (!value || typeof value !== 'object') return null;
+  // A class the choice leaves out keeps its default, which is shown: a
+  // partial request (`{debris: false}`) hides only what it names.
+  const letters = SATELLITE_CLASS_LETTERS.filter(([id]) => value[id] !== false)
+    .map(([, letter]) => letter)
+    .join('');
+  return letters || '0';
+}
+
+/**
+ * The class choice the letters stand for, without Starlink, or null.
+ * @param {string} mask
+ * @returns {Record<string, boolean>|null}
+ */
+export function decodeSatelliteClassMask(mask) {
+  const normalized = normalizeSatelliteClassMask(mask);
+  if (normalized === null || typeof mask !== 'string') return null;
+  return Object.fromEntries(
+    SATELLITE_CLASS_LETTERS.map(([id, letter]) => [
+      id,
+      normalized.includes(letter),
+    ]),
+  );
+}

src/layers/satellites/controls.js

@@ -1,4 +1,5 @@
 import { satelliteClassText } from '../../data/satelliteClass.js';
+import { decodeSatelliteClassMask } from '../../data/satelliteClassMask.js';
 import * as Cesium from 'cesium';
 import { t } from '../../i18n/index.js';
 import {
@@ -493,16 +494,22 @@ export function createControls({ state: layerState, services, parts, source }) {
       let catalog = params.catalog;
       if (catalog !== undefined && catalog !== 'core' && catalog !== 'dense')
         return false;
+      // A saved or shared choice arrives as class letters (layerState.js).
+      const requestedClasses =
+        typeof params.classes === 'string'
+          ? decodeSatelliteClassMask(params.classes)
+          : params.classes;
       if (params.classes !== undefined) {
-        if (!params.classes || typeof params.classes !== 'object') return false;
+        if (!requestedClasses || typeof requestedClasses !== 'object')
+          return false;
         // Starlink's toggle is the dense catalog: its points load on demand.
         if (
-          typeof params.classes.starlink === 'boolean' &&
+          typeof requestedClasses.starlink === 'boolean' &&
           catalog === undefined
         )
-          catalog = params.classes.starlink ? 'dense' : 'core';
+          catalog = requestedClasses.starlink ? 'dense' : 'core';
         layerState._params.classes = mergeClassVisibility(
-          params.classes,
+          requestedClasses,
           _classes(),
         );
       }

src/share/viewCodec.js

@@ -273,7 +273,11 @@ export const SHARE_VIEW_LAYER_OPTION_ABSENT = Object.freeze({
     selectedFlightsTrackingId: null,
     selectedMilitaryTrackingId: null,
   }),
-  satellites: Object.freeze({ catalog: 'core', selectedSatTrackingId: null }),
+  satellites: Object.freeze({
+    catalog: 'core',
+    selectedSatTrackingId: null,
+    classes: 'sitpd',
+  }),
   cctv: Object.freeze({
     coverageMode: 'on',
     showProjection: true,