Merge upstream/main: Street View rework meets i18n

Upstream's Street View rework (second imagery provider, one source at a
time, OPEN STREET VIEW button, key-alternative guidance) rewrote exactly
the street-level regions this branch localizes.

Resolved as upstream logic + re-applied localization:

- keySetupCore: new unlock copy kept as msg() data; added
  keySetupAlternativeKeyNames() returning machine values (registry key
  names) so key-setup core stays English while presentation localizes.
- New src/ui/keyGuidance.js: localized key-guidance composer shared by
  layerPanel and streetLevelPresentation (requirement sentence plus the
  "or light X to use your Y key" alternatives tail, placeholders only).
- streetLevelPresentation: keyGuidance()/presentNearest()/presentMeta
  relocalized (t/tn + formatNumber instead of toLocaleString);
  renderModes and month-precision dates kept from upstream.
- layer-panels.html: upstream row ids, sl-meta-row and the new button
  kept, data-i18n hooks re-applied (incl. OPEN STREET VIEW fallback).
- es/ru catalogs: 13 new keys, stale unlock key replaced in place.

npm run i18n: complete for es and ru. npm test: 6345/6347; the one
failure (devFreshDotenv provenance) also fails on plain upstream/main
and on the pre-merge tip here - this machine leaks OPENAI_API_KEY into
spawned children with a replaced env, so it is environmental.

src/app/layers/streetLevel.js

@@ -1,21 +1,33 @@
 import { createStreetLevelLayer } from '../../layers/streetLevel/index.js';
 import { createMapillaryProvider } from '../../layers/streetLevel/providers/mapillary/index.js';
+import { createGoogleProvider } from '../../layers/streetLevel/providers/google/index.js';
 import * as sprites from '../../data/spriteOrder.js';
 import * as picking from '../../data/pickRegistry.js';
 import * as input from '../../data/inputOwnership.js';
+import * as scenePick from '../../data/scenePick.js';
 import * as render from '../../renderGovernor.js';
 
+/** The browser Maps key the scene was started with (src/app/scene.js). */
+const googleApiKey = () => globalThis.window?.__GOOGLE_MAPS_API_KEY__ || null;
+
+/** Mapillary and Google Street View, once the Mapillary source is supplied; else none. */
+function defaultProviders(sources) {
+  if (sources.mapillary == null) return [];
+  return [
+    createMapillaryProvider({ source: sources.mapillary }),
+    createGoogleProvider({ getApiKey: googleApiKey }),
+  ];
+}
+
 /**
- * Inject providers, or use Mapillary only when its source is supplied.
- * An explicit provider list replaces the default; unused sources.mapillary is
- * neither constructed nor validated, including when the list is empty.
+ * Inject providers, or use the defaults. An explicit provider list replaces
+ * them; an unused sources.mapillary is neither constructed nor validated,
+ * including when the list is empty.
  */
 export function createApplicationStreetLevel({
   surface,
   sources = {},
-  providers = sources.mapillary == null
-    ? []
-    : [createMapillaryProvider({ source: sources.mapillary })],
+  providers = defaultProviders(sources),
 }) {
   return createStreetLevelLayer({
     providers,
@@ -23,6 +35,7 @@ export function createApplicationStreetLevel({
       sprites,
       picking,
       input,
+      scenePick,
       render,
       ground: surface?.groundFloor ?? null,
       meshFloor: surface?.meshFloor ?? null,

src/app/layers/streetLevel.test.mjs

@@ -27,3 +27,25 @@ test('explicit providers replace the default source and an empty list removes it
     /array/,
   );
 });
+
+test('the defaults are Mapillary (given its source) and Street View, which starts off and travels as a provider switch', async () => {
+  const { createDefaultLayerState } = await import('../../data/layerState.js');
+  const mapillary = {
+    getStatus() {},
+    getTile() {},
+    getSequenceImages() {},
+    nearestImages() {},
+  };
+  const layer = createApplicationStreetLevel({ sources: { mapillary } });
+  assert.deepEqual(layer.providerIds, ['mapillary', 'google']);
+  // A fresh page and a restored default agree: Street View is billed, so off.
+  layer.setParams(createDefaultLayerState().options['street-level']);
+  assert.equal(layer.getParams().google, false);
+  assert.equal(layer.getParams().mapillary, true);
+  // A link that lit Street View carries it in the shared switch field.
+  layer.setParams({ providerSwitches: 'google-1' });
+  assert.equal(layer.getParams().google, true);
+  assert.equal(layer.getParams().providerSwitches, 'google-1');
+  // Without the application's Street Level source there are none.
+  assert.deepEqual(createApplicationStreetLevel({}).providerIds, []);
+});