chore: add loadtest observability setup

deploy/env/api-server.env.example

@@ -5,6 +5,12 @@ GENARRATIVE_ENV=production
 GENARRATIVE_API_HOST=127.0.0.1
 GENARRATIVE_API_PORT=8082
 GENARRATIVE_API_LOG=info,tower_http=info
+GENARRATIVE_API_LISTEN_BACKLOG=1024
+GENARRATIVE_API_WORKER_THREADS=4
+GENARRATIVE_OTEL_ENABLED=false
+OTEL_SERVICE_NAME=genarrative-api
+OTEL_EXPORTER_OTLP_ENDPOINT=http://127.0.0.1:4318
+OTEL_RESOURCE_ATTRIBUTES=deployment.environment=production,service.namespace=genarrative
 
 GENARRATIVE_ADMIN_USERNAME=
 GENARRATIVE_ADMIN_PASSWORD=