feat(listings): phase A — surface usableAreaM2, floor/totalFloors, metroDistanceM

The Property table already stores usableAreaM2, floor, totalFloors,
metroDistanceM and nearbyPOIs but the listing detail endpoint was
dropping them. Add them to ListingDetailData + the Prisma read query,
mirror the additions on the frontend ListingDetail type, and render
them on the detail page:

- Quick-specs bar now shows "Tầng X / Y" (floor/totalFloors) with a
  sensible fallback to `floors`, plus "Cách metro" when populated.
- Details card adds rows: "Diện tích sử dụng", "Tầng / Tổng tầng"
  (merges floor + totalFloors), "Cách metro gần nhất" (formatted m/km).
- New "transit" icon for the metro stat.

Purely additive surfacing — no schema change, no migration. Listings
missing these fields still render as before.

Test fixture in listing-detail-client.spec.tsx extended with the new
nullable fields so the type stays compatible.

Phase A of 4 (Listings detail enhancement plan).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/modules/listings/domain/repositories/listing-read.dto.ts

@@ -28,13 +28,18 @@ export interface ListingDetailData {
     latitude: number;
     longitude: number;
     areaM2: number;
+    usableAreaM2: number | null;
     bedrooms: number | null;
     bathrooms: number | null;
     floors: number | null;
+    floor: number | null;
+    totalFloors: number | null;
     direction: Direction | null;
     yearBuilt: number | null;
     legalStatus: string | null;
     amenities: unknown;
+    nearbyPOIs: unknown;
+    metroDistanceM: number | null;
     projectName: string | null;
     media: ListingMediaData[];
   };

apps/api/src/modules/listings/infrastructure/repositories/listing-read.queries.ts

@@ -62,13 +62,18 @@ export async function findByIdWithProperty(
       latitude: geo.latitude,
       longitude: geo.longitude,
       areaM2: listing.property.areaM2,
+      usableAreaM2: listing.property.usableAreaM2,
       bedrooms: listing.property.bedrooms,
       bathrooms: listing.property.bathrooms,
       floors: listing.property.floors,
+      floor: listing.property.floor,
+      totalFloors: listing.property.totalFloors,
       direction: listing.property.direction,
       yearBuilt: listing.property.yearBuilt,
       legalStatus: listing.property.legalStatus,
       amenities: listing.property.amenities,
+      nearbyPOIs: listing.property.nearbyPOIs,
+      metroDistanceM: listing.property.metroDistanceM,
       projectName: listing.property.projectName,
       media: listing.property.media.map((m) => ({
         id: m.id,