Merge origin/main: Google Street View provider, translated

Main added the Google Street View street-level provider and key guidance
that offers another source. Its new text goes through t()/msg() with ru
and es entries; the key guidance the panel shows is built in the UI
language by src/ui/keyGuidance.js, while keySetupCore.mjs keeps the
English sentences the server and AI tools use.

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

CHANGELOG.md

@@ -109,6 +109,19 @@
 
 ## [Unreleased]
 
+- Street Level: Google Street View is the second provider. On the Google 3D
+  map (Google's terms keep it off other maps), light its chip (off by
+  default: every panorama is billed to the Google Maps key, which needs the
+  Maps JavaScript API) and click a street, or press OPEN STREET VIEW, to
+  open Google's own panorama in
+  the panel, with its arrows, the address and month in the caption, a link
+  to Google Maps and FOLLOW. Share links carry it in the provider switches
+  (`r.google-1`). One provider is lit at a time (lighting one switches the
+  other off), Mapillary by default since it is free. Street View's panoramas
+  are all 360°, so the IMAGERY and SINCE filters and the legend apply to
+  Mapillary only and hide while GOOGLE STREET VIEW is lit; its globe marker
+  is a Google-blue view cone.
+
 - Add an experimental ChatGPT/Codex OAuth option for cloud voice in Provider
   Settings. API-key voice remains the default. Local sign-in can start from
   the auth button and reports completion, failure, timeout, or expired