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/ui/streetLevelPresentation.js

@@ -80,6 +80,8 @@ function presentProviders(state) {
     else if (keyRequired && provider.requiresKeyId)
       title = `${provider.name}: ${keySetupRequirement(provider.requiresKeyId)}`;
     else if (provider.error) title = `${provider.name}: ${provider.error}`;
+    // Usable only on another map stack (Street View off Google 3D).
+    else if (provider.unavailable) title = provider.unavailable;
     return {
       id: provider.id,
       label: provider.label,
@@ -89,11 +91,13 @@ function presentProviders(state) {
       disabled: false,
       state: keyRequired
         ? 'error'
-        : on && provider.loading
-          ? 'loading'
-          : on
-            ? 'active'
-            : 'idle',
+        : on && provider.unavailable
+          ? 'warn'
+          : on && provider.loading
+            ? 'loading'
+            : on
+              ? 'active'
+              : 'idle',
       busy: on && provider.loading === true,
     };
   });

src/ui/styles/street-level.css

@@ -183,6 +183,12 @@ button.sl-status:focus-visible {
   border-color: rgba(255, 179, 0, 0.55);
 }
 
+/* On, but not usable on this map stack (Street View off Google 3D). */
+.sl-chips .data-toggle-chip.chip-warn {
+  opacity: 0.7;
+  border-style: dashed;
+}
+
 /* ── Errors ──────────────────────────────────────────────────────────────── */
 .sl-error {
   font-family: var(--font-sans);