fix(street-level): IC8 review of the Street View provider

Google's Maps Platform terms forbid Street View imagery beside non-Google
maps, so the provider declares requiresMapStack: 'photoreal': off Google
3D its chip is dashed with the reason, lookups and opens skip it, and
leaving Google 3D closes its panorama.

- Ground clicks: only a click on the map itself (scenePick.isSurfacePick:
  nothing picked or Google 3D tile content) at street zoom opens Street
  View, and the camera stays put; higher up the hint says to zoom in.
  scenePick.pickGroundPosition replaces the copy in Directions.
- Viewer: poses go out at once and again when the date and address
  arrive, so an open never hangs on that lookup; one lookup per panorama,
  seeded by the nearest lookup; a close settles a pending open; failed
  lookups are asked again; poses follow position changes, not pano_changed.
- Loader: the gm_authFailure handler is installed once, so a retried load
  reports a refusal once.
- Viewer host: a prewarm that lands after another provider took the host
  is released; FIT/FILL availability is set on every open.
- Provider: a refusal while switched off reports no error over another
  photo; SINCE compares against the end of Google's month; messages name
  the referrer and network causes; FLAT says Street View is 360° only.
- The layer row names the key of the providers that are on; the MCP panel
  CSP admits Street View's tiles, control images and photos.
- Tests for each, against fakes that now follow Google's event order; the
  browser gate restores its state, waits instead of sleeping, aims its
  panel clicks and corner drags, and asserts the camera stays put.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/layers/streetLevel.test.mjs

@@ -0,0 +1,27 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createApplicationStreetLevel } from './streetLevel.js';
+import { createDefaultLayerState } from '../../data/layerState.js';
+
+test('each provider starts as its share-link option does, so a fresh page and a restored one agree', () => {
+  const layer = createApplicationStreetLevel({
+    surface: null,
+    sources: {
+      mapillary: {
+        getStatus() {},
+        getTile() {},
+        getSequenceImages() {},
+        nearestImages() {},
+      },
+    },
+  });
+  const options = createDefaultLayerState().options['street-level'];
+  const providers = layer.getUIState().providers;
+  assert.deepEqual(
+    providers.map((p) => p.id),
+    layer.providerIds,
+  );
+  for (const provider of providers)
+    assert.equal(provider.on, options[provider.id], provider.id);
+  assert.equal(options.google, false, 'Street View is billed: off');
+});