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/layers/streetLevel/selection.test.mjs

@@ -67,7 +67,8 @@ function harness({ selected = false } = {}) {
     parts: {
       router: { ownsPick: (id) => id === 'mly:seq:1', resolve: () => null },
       hasSelectedSequence: () => sequences.selected,
-      openAtGround: (position) => groundClicks.push(position),
+      openAtGround: (position, picked) =>
+        groundClicks.push({ position, picked }),
       clearSequences() {
         sequences.cleared++;
         sequences.selected = false;
@@ -264,15 +265,19 @@ test('Esc in a text field or rich-text editor keeps the selection (M61)', () =>
   }
 });
 
-test('a click on bare ground goes to the ground handler; a click on anything with an id does not', () => {
+test('a click on nothing of ours goes to the ground handler with the pick, which decides', () => {
   const h = harness();
   try {
     h.click(5);
-    assert.deepEqual(h.groundClicks, [{ x: 5, y: 10 }]);
-    // Another layer's aircraft, or an id nobody registered: not the ground.
     h.scene.under = 'flight:abc';
     h.click(6);
-    assert.equal(h.groundClicks.length, 1);
+    assert.deepEqual(
+      h.groundClicks.map(({ position, picked }) => [position.x, picked?.id]),
+      [
+        [5, undefined],
+        [6, 'flight:abc'],
+      ],
+    );
   } finally {
     h.restore();
   }