The Coach self-context loader failed soft per field (undecryptable
allergies/conditions → null) with no signal, so a key-rotation gap made
the Coach generate guidance without ever seeing the user's recorded
allergies, indistinguishable from an empty profile. Keep the per-field
fail-closed posture but emit a wide-event on each swallowed decrypt and on
the DB-read guard, so a systemic failure surfaces instead of masquerading
as 'the user never wrote anything'.