HouseholdMembers

PATCH /v1/households/{id}/members/{member} request body. Partial-update wire shape (UpdateRecipeRequestData convention) — every field is `Optional` so omitting it means "leave * unchanged". Sending an explicit `null` on a nullable field means "clear it". Per Req 10 / D-24, the controller layer rejects diet+dislikes mutations for account-linked members (user_id NOT NULL) — the server-side check lives in {@see UpdateHouseholdMemberCommandHandler} because the membership state isn't available at request-validation time without a DB lookup. : `role` field REMOVED — the per-plate adult/child taxonomy is gone. `birth_date` (nullable CarbonImmutable) added; clearing requires explicit null. `diet` is constrained to the same enum used by `users.dietary_preferences.diet_type` (Req 9 / D-23).