Add sourceMap: true to backend tsconfig.json

apps/backend/tsconfig.json

@@ -1,6 +1,7 @@
 {
   "extends": ["@tsconfig/node23/tsconfig.json", "@tsconfig/node-ts/tsconfig.json"],
   "compilerOptions": {
+    "sourceMap": true,
     "outDir": "dist"
   }
 }