Introduce two structured health-record tables, kept as reference records
(not time-series signals):
- `allergies` — AllergyIntolerance-style: substance + category + type +
severity + status + optional onset. The substance label stays queryable
plaintext; the free-text reaction and note are AES-256-GCM encrypted
(`reaction_encrypted` / `notes_encrypted` BYTEA).
- `family_history_entries` — one condition per relative: relationship +
condition label + optional age-at-onset; the free-text note is encrypted.
Both are owner-scoped and soft-deleted. Migrations 0215/0216 are additive
and idempotent. The three new encrypted columns are registered in
ENCRYPTED_COLUMNS and wired into the key-rotation script, so a key drop can
never silently strand them undecryptable.
