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.

scripts/package-boundaries.json

@@ -1286,7 +1286,8 @@
     "exports": [
       "./layers/street-level",
       "./layers/street-level/mapillary",
-      "./layers/street-level/mapillary/source"
+      "./layers/street-level/mapillary/source",
+      "./layers/street-level/google"
     ],
     "modules": [
       "src/layers/streetLevel/index.js",
@@ -1315,6 +1316,11 @@
       "src/layers/streetLevel/tileMath.js",
       "src/layers/streetLevel/selection.js",
       "src/layers/streetLevel/providers/mapillary/viewer.js",
+      "src/layers/streetLevel/groundClick.js",
+      "src/layers/streetLevel/providers/google/index.js",
+      "src/layers/streetLevel/providers/google/policy.js",
+      "src/layers/streetLevel/providers/google/viewer.js",
+      "src/layers/streetLevel/providers/google/mapsLoader.js",
       "src/layers/streetLevel/providers/mapillary/source.js",
       "scripts/qa-street-level.mjs",
       "src/i18n/index.js",
@@ -2290,6 +2296,11 @@
       "src/layers/streetLevel/tileMath.js",
       "src/layers/streetLevel/selection.js",
       "src/layers/streetLevel/providers/mapillary/viewer.js",
+      "src/layers/streetLevel/groundClick.js",
+      "src/layers/streetLevel/providers/google/index.js",
+      "src/layers/streetLevel/providers/google/policy.js",
+      "src/layers/streetLevel/providers/google/viewer.js",
+      "src/layers/streetLevel/providers/google/mapsLoader.js",
       "src/layers/streetLevel/providers/mapillary/source.js",
       "src/app/layers/streetLevel.js",
       "src/layers/alpr/tileRecords.js",
@@ -2820,6 +2831,11 @@
       "src/layers/streetLevel/tileMath.js",
       "src/layers/streetLevel/selection.js",
       "src/layers/streetLevel/providers/mapillary/viewer.js",
+      "src/layers/streetLevel/groundClick.js",
+      "src/layers/streetLevel/providers/google/index.js",
+      "src/layers/streetLevel/providers/google/policy.js",
+      "src/layers/streetLevel/providers/google/viewer.js",
+      "src/layers/streetLevel/providers/google/mapsLoader.js",
       "src/layers/streetLevel/providers/mapillary/source.js",
       "src/app/layers/streetLevel.js",
       "src/layers/alpr/tileRecords.js",