plugins.isolation: host imports every non-bundled plugin in a host process started
on demand per profile with only that profile's environment, and hands plugins a
RemotePluginContext; Hermes registers proxies for tools, hooks, commands, skills and
provider objects (subclasses of the ABC it checks). Re-entrant: handlers may call
ctx back into Hermes while Hermes waits on them. Every user-code import path routes
to the host (general, memory/context-engine/cron, model-provider profiles via a
cached credential-free extraction, dashboard APIs via an ASGI bridge) or refuses.
One table names what cannot cross (live gateway objects); the static audit shown
by `hermes plugins validate/show` reads it. A host that dies is restarted with its
plugins (bounded). Default stays in_process: nothing changes unless opted in.
Why: shared-pool deployments must never run one tenant's plugin Python in an
interpreter holding another tenant's data, without plugins becoming tenant-aware.
