fix(gists): dynamic radius with ST_DWithin and distance in response

Backend/src/gists/entities/gist.entity.ts

@@ -3,6 +3,7 @@ import { Entity, PrimaryGeneratedColumn, Column, CreateDateColumn, Index } from
 @Entity('gists')
 @Index('idx_gists_location_cell')
 @Index('idx_gists_author_address')
+@Index('idx_gists_location_geography', { synchronize: false })
 export class Gist {
   @PrimaryGeneratedColumn('uuid')
   id: string;

Backend/src/gists/gist.repository.ts

@@ -92,7 +92,7 @@ export class GistRepository {
 
     const extraWhere = `AND ${clauses.join(' AND ')}`;
 
-    const items = await this.dataSource.query<Gist[]>(
+    const rows = await this.dataSource.query<Array<Gist & { distance_meters: string }>>(
       `
       SELECT
         g.id,
@@ -107,22 +107,28 @@ export class GistRepository {
         ST_X(g.location::geometry)                              AS lon,
         ST_Y(g.location::geometry)                              AS lat,
         ST_Distance(
-          g.location,
+          g.location::geography,
           ST_SetSRID(ST_MakePoint($1, $2), 4326)::geography
         )                                                        AS distance_meters
       FROM gists g
       WHERE ST_DWithin(
-        g.location,
+        g.location::geography,
         ST_SetSRID(ST_MakePoint($1, $2), 4326)::geography,
         $3
       )
+      AND g.expires_at > NOW()
       ${extraWhere}
       ORDER BY distance_meters ASC, g.created_at DESC
       LIMIT $4
       `,
       params,
     );
 
+    const items: Gist[] = rows.map((r) => ({
+      ...r,
+      distanceMeters: parseFloat(r.distance_meters),
+    }));
+
     return PaginationHelper.buildResponse(items, limit);
   }