feat: endpoint GET /locations/cities/all para lista plana de ciudades

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/locations/locations.controller.ts

@@ -9,6 +9,9 @@ export class LocationsController {
   constructor(private locations: LocationsService) {}
 
   // Public reads
+  @Get('cities/all')
+  getAllCities() { return this.locations.getAllCities(); }
+
   @Get('countries')
   getCountries() { return this.locations.getCountries(); }
 

backend/src/locations/locations.service.ts

@@ -5,6 +5,13 @@ import { PrismaService } from '../prisma/prisma.service';
 export class LocationsService {
   constructor(private prisma: PrismaService) {}
 
+  getAllCities() {
+    return this.prisma.cities.findMany({
+      orderBy: { name: 'asc' },
+      select: { id: true, name: true },
+    });
+  }
+
   getCountries() {
     return this.prisma.countries.findMany({
       include: { regions: { include: { cities: true }, orderBy: { name: 'asc' } } },