Directions deeplinks use stored coordinates, not address string

A directions deeplink that passes an address string instead of stored coordinates requires the maps app to re-geocode the address on the user's device. This introduces latency, geocoding ambiguity (a common street name in multiple cities can resolve to the wrong location), and dependency on network availability. CWE-682 (Incorrect Calculation) applies when coordinates are derived from address at deeplink-construction time instead of retrieved from storage. Schema.org GeoCoordinates exists precisely to make precise lat/lng available for machine consumption — ignoring it in favor of address string passing defeats the purpose of storing coordinates at all.

Use the stored latitude and longitude values directly in deeplink construction. Never use the address string as the deeplink destination parameter.

// CORRECT: stored coordinates
const deeplink = `https://maps.google.com/?daddr=${listing.latitude},${listing.longitude}`;

// WRONG: address string — forces re-geocoding with ambiguity risk
const deeplink = `https://maps.google.com/?daddr=${encodeURIComponent(listing.address)}`;

In src/components/ListingDetail.tsx (or equivalent), confirm that the directions link reads from listing.latitude / listing.longitude fields, not listing.address. If those fields are not currently included in the listing query, add them to the select — they should already be in the database per directory-map-location.map-rendering.coordinates-stored-explicit.