feat: enhance createSport functionality with conflict handling and result management

Co-authored-by: Copilot <copilot@github.com>

apps/backend/src/modules/sport/services/sport.service.ts

@@ -1,6 +1,7 @@
 import { Prisma, Sport } from '@/generated/prisma/client';
+import { Errors } from '@/lib/errors';
 import { db } from '@/lib/prisma';
-import { ok, Result } from '@/lib/result';
+import { err, ok, Result } from '@/lib/result';
 import { v7 as uuidv7 } from 'uuid';
 
 export type CreateSportInput = {
@@ -62,7 +63,15 @@ export async function listSports(): Promise<Result<Sport[]>> {
 export async function createSport(input: CreateSportInput) {
   const slug = await buildUniqueSlug(input.name);
 
-  return db.sport.create({
+  const existing = await db.sport.count({
+    where: { slug },
+  });
+
+  if (existing > 0) {
+    return err(Errors.conflict('Ya existe un deporte con ese nombre.'));
+  }
+
+  var created = db.sport.create({
     data: {
       id: uuidv7(),
       name: input.name.trim(),
@@ -70,6 +79,8 @@ export async function createSport(input: CreateSportInput) {
       isActive: true,
     },
   });
+
+  return ok(created);
 }
 
 export async function getSportById(id: string) {