session-controller registers its resolver through `ctx.fileUploads`. Inside
that call Cordis returns a new proxy for every function-valued property read
from `this`, so the disposer's identity check never matched and the slot was
never cleared. Any restart of session-controller, such as a profile patch that
changes session-query-sqlite, then failed with "Agent resolver is already
registered" and left every sessionController dependent pending.
Store the resolver in a plain holder object, as the commands receipt resolver
already does, and test registration and disposal through a plugin fiber.