Add registry and fallbackRegistries to the manager Config, ask them in
order from inspect and installBundle with --registry, and move on only
for failures another registry can change: unreachable, timed out, or a
copy the registry lacks. A git or tarball spec's own host is never
retried through a registry, and a registry outside the configured set
is asked alone. The lookup runs without pnpm's retries so a dead
registry is reported within inspectTimeoutMs; the install keeps pnpm's
defaults. Results carry the registries asked, the install-state event
names each attempt, and the plugin_manager tool takes a registry.
imccyu