feat(street-level): OPEN STREET VIEW, and Street View only on Google 3D

- OPEN STREET VIEW in the PROVIDERS row opens Street View's nearest
  panorama at the ground under the middle of the screen, without moving
  the camera: Street View no longer needs a pointer. It is disabled (and
  says so) until the camera is at street zoom.
- Off the Google 3D map Street View does not appear at all: no chip,
  legend swatch, globe credit, layer source or button, and Google's script
  is not loaded (the viewer has no prewarm; the script loads on first use).
  The share option keeps the user's choice for when Google 3D returns.
- A ground click measures the camera height at the click rather than
  reading the cached flag.
- A chip without a usable key explains it instead of lighting; it darkens
  beside a lit chip, and the other chips keep switching, so a refused
  Street View key cannot lock Mapillary out.
- The gate checks that nothing of Street View shows off Google 3D even when
  a share link switches it on, presses OPEN STREET VIEW on Google 3D, and
  asserts that each chip it switches really switched.

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

src/layers/streetLevel/groundClick.js

@@ -15,15 +15,24 @@ export function groundClickHeightOk(viewer, groundAt) {
  * street zoom opens the nearest image of the active, available providers
  * that have no coverage to click (`groundClick`, Google Street View). The
  * camera stays put: the user chose the spot.
- * @param {{state: object, openNearest: Function, isAvailable: (entry: object) => boolean}} options
+ * The height is measured at the click, not read from the cached flag.
+ * @param {{state: object, openNearest: Function, isAvailable: (entry: object) => boolean, groundAt?: Function}} options
  * @returns {(screenPosition: {x: number, y: number}, picked?: object) => Promise<boolean>|false}
  */
-export function createGroundClick({ state, openNearest, isAvailable }) {
+export function createGroundClick({
+  state,
+  openNearest,
+  isAvailable,
+  groundAt = null,
+}) {
   return function openAtGround(screenPosition, picked) {
     const scenePick = state.services.scenePick;
     if (!state.enabled || !state.viewer || !scenePick?.pickGroundPosition)
       return false;
-    if (!scenePick.isSurfacePick(picked) || !state.groundClickReady)
+    if (
+      !scenePick.isSurfacePick(picked) ||
+      !groundClickHeightOk(state.viewer, groundAt)
+    )
       return false;
     const providerIds = [...state.providers.values()]
       .filter(