Reveal-in-file-manager was always offered whenever the server exposed
revealPath, including in a plain browser tab where there is no local
file manager to reveal into. Gate it behind a new isBrowserClientRuntime
check (web platform, no Electron shell) and relabel the save action to
"Download" for that case, since it triggers a browser-style file
download rather than an in-place save.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
