Server actions: request tracker never intercepts action POST when node-runtime middleware is configured

This issue was created by an agent analysing CI failures from the Next.js Deploy Suite (vinext main vs Next.js v16.2.6, 2026-05-22).

Problem

Tests that invoke a server action with a serverActions.bodySizeLimit config under a node-runtime middleware never see the expected action POST request fire (Did not intercept a request within 5000ms). The action endpoint appears to be short-circuited by the node middleware instead of being dispatched.

Did not intercept a request within 5000ms (server action POST under node middleware)

Estimated Impact

~5 test failures across the deploy suite.

Affected Test Suites

• test/e2e/app-dir/actions/app-action-size-limit-invalid-node-middleware.test.ts (5 failures)

Recommendation

1. Reproduce first in vinext's own test suite. Add a server action inside an app that also defines a node-runtime middleware.ts. Submit the action and assert the POST request is observed by the test runner.

2. Route action POSTs through middleware properly. Ensure that, after node middleware decides to fall through, the server-action POST is dispatched to the action handler rather than being swallowed.

3. Also check the bodySizeLimit enforcement path. The original suite is app-action-size-limit-invalid-node-middleware; verify the body-size-limit enforcement still runs after middleware.