Ritz-Carlton grants “Reserve” to only a handful of properties on earth — intimate, landscape-first sanctuaries a tier above the brand’s hotels — and Zadún was the first in Mexico: one hundred fifteen rooms, suites, and villas dissolved into forty-two low buildings across twenty hillside acres, every one with a plunge pool, a butler, and the Sea of Cortez filling the glass. The effect is closer to a private estate than a resort.   Zadún sits inside gated Puerto Los Cabos on the San José side — fifteen minutes from the airport, five from the gallery district, in the orbit of Flora Farms and Acre — the connoisseur’s corner of Los Cabos, where the destination’s best food and quietest beaches share a zip code.