a0977b0a3c
A backend that predates the `profile` response field left the owner key's
profile empty, while the resume path records the same session under
{connectionId, profile: 'default'}. Two entries per backend meant the
owner-hint lookup only ever saw the resume entry and the no-hint fallback
returned nothing — "Show earlier" stayed hidden for exactly the mixed
Desktop/backend versions the PR body says remain readable.
An absent field now falls back to the ambient request profile ('default'
when none is active): that IS the profile an untagged read lands on. A
`null` field (custom HERMES_HOME) still stays distinct from 'default'.