test(node): Auto-flush node-integration-tests via beforeExit (#20960)

Removes the `setInterval(() => {}, 1000)` boilerplate from 46
integration-test scenarios by injecting a `beforeExit` auto-flush hook
from the runner instead.

**Why the boilerplate existed.** Most scenarios end synchronously after
queuing spans/events. The OTel batch processor and Sentry client flush
asynchronously, so without a live handle Node exits before envelopes
reach the (logging) transport. Each scenario kept the loop alive with a
`setInterval`; the runner SIGTERMed the child once it had seen the
expected envelopes.

**What replaces it.** A small `auto-flush.{cjs,mjs}` loader injected via
`--require` / `--import` registers a `process.on('beforeExit', () =>
Sentry.flush(2000))`. When the loop drains, the awaited flush keeps it
alive until queued envelopes are sent, then the process exits naturally
— no setInterval, no SIGTERM handler interaction, no force-exit timer.

Two loader variants because Node's CJS and ESM module caches are
separate: ESM scenarios get `auto-flush.mjs` so `import * as Sentry`
resolves to the same SDK instance the scenario uses; CJS gets
`auto-flush.cjs`. The runner picks the right one based on whether
`flags` already contain `--import`.

Skipped when no envelopes are expected (e.g. ANR `should-exit`,
`ensureNoErrorOutput`) — those tests assert the child exits naturally
and auto-flush would delay them by retrying HTTP requests against the
fake DSN.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mydea

dev-packages/node-integration-tests/suites/tracing/amqplib/scenario.mjs

@@ -32,9 +32,6 @@ const QUEUE_OPTIONS = {
 
   await channel.close();
   await connection.close();
-
-  // Stop the process from exiting before the transaction is sent
-  setInterval(() => {}, 1000);
 })();
 
 async function connectToRabbitMQ() {

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/scenario-error.js

@@ -8,9 +8,6 @@ Sentry.init({
   transport: loggingTransport,
 });
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const gql = require('graphql-tag');
   const server = require('./apollo-server')();

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/scenario-mutation.js

@@ -8,9 +8,6 @@ Sentry.init({
   transport: loggingTransport,
 });
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const gql = require('graphql-tag');
   const server = require('./apollo-server')();

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/scenario-query.js

@@ -8,9 +8,6 @@ Sentry.init({
   transport: loggingTransport,
 });
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('./apollo-server')();
 

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-invalid-root-span.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('../apollo-server')();
 

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-multiple-operations-many.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('../apollo-server')();
 

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-multiple-operations.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('../apollo-server')();
 

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-mutation.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const gql = require('graphql-tag');
   const server = require('../apollo-server')();

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-no-operation-name.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('../apollo-server')();
 

dev-packages/node-integration-tests/suites/tracing/apollo-graphql/useOperationNameForRootSpan/scenario-query.js

@@ -11,9 +11,6 @@ const client = Sentry.init({
 
 const tracer = client.tracer;
 
-// Stop the process from exiting before the transaction is sent
-setInterval(() => {}, 1000);
-
 async function run() {
   const server = require('../apollo-server')();