fix(sse): prevent client-abort (aborted/ECONNRESET) from crashing the server (#11556)

Merged via /merge-batch (lote 2026-08-26, v3.8.51). Boarded no worktree combinado junto com outras ~30 PRs; validação única: typecheck/complexity/cognitive-complexity/changelog-integrity verdes, file-size rebaseado onde necessário (crescimento legítimo), lint com os mesmos 228 achados pré-existentes confirmados via sonda contra o tip puro (não introduzidos por este lote), e ~370 testes focados (unit + vitest) passando. Obrigado pela contribuição.

scripts/dev/httpClientAbortGuard.mjs

@@ -0,0 +1,17 @@
+"use strict";
+
+/**
+ * Re-export of the shared client-abort guard so the Node-only dev server
+ * (`run-next.mjs`) keeps importing from its original relative path. The real
+ * implementation lives in `src/shared/utils/httpClientAbortGuard.mjs` (importable
+ * from both `.mjs` and the TypeScript servers under `src/`, tsconfig allowJs).
+ *
+ * @module
+ */
+
+export {
+  isClientAbortError,
+  shouldSwallowUncaught,
+  attachRequestStreamGuards,
+  installProcessCrashGuard,
+} from "../../src/shared/utils/httpClientAbortGuard.mjs";

scripts/dev/run-next.mjs

@@ -16,6 +16,10 @@ import { isTurbopackCacheCorruption, purgeAllTurbopackCaches } from "./turbopack
 import { randomUUID } from "node:crypto";
 import { getMainServerTimeoutConfig } from "./main-server-timeouts.mjs";
 import { createSystemdNotifier } from "./systemd-notify.mjs";
+import {
+  attachRequestStreamGuards,
+  installProcessCrashGuard,
+} from "./httpClientAbortGuard.mjs";
 
 const { maybeHandleDisallowedMethod } = methodGuard;
 const { wrapRequestListenerWithHeadResponseGuard } = headResponseGuard;
@@ -162,6 +166,13 @@ async function prepareWithHeal() {
 }
 
 async function start() {
+  // Safety net: a client aborting a connection (browser navigation, HMR reconnect,
+  // Back/Forward cache) can emit `Error: aborted`/`ECONNRESET` on the request
+  // stream. Without this the single missed listener becomes an uncaughtException
+  // that takes the whole server down — surfacing as a wall of ERR_CONNECTION_REFUSED
+  // after login. Benign aborts are swallowed; genuine errors still crash loudly.
+  installProcessCrashGuard();
+
   await prepareWithHeal();
 
   const requestHandler = nextApp.getRequestHandler();
@@ -176,6 +187,10 @@ async function start() {
 
   const server = http.createServer(
     wrapRequestListenerWithHeadResponseGuard((req, res) => {
+      // Absorb client-abort errors (browser closes the socket during
+      // navigation/HMR/bfcache) on the request/response streams so they never
+      // surface as an uncaughtException that kills the whole server (#fix-dev-server-aborted).
+      attachRequestStreamGuards(req, res);
       if (maybeHandleDisallowedMethod(req, res)) return;
       // Stamp the real TCP peer IP before Next sees the request, so the authz
       // middleware can decide LOCAL_ONLY locality without trusting the Host header.