fix(dev): stop stale frontend when portal exits

scripts/dev-core.mjs

@@ -12,6 +12,7 @@ import {
   deepseekDisableThinkingEnabled,
   resolveDeepseekNoThinkListenPort,
 } from '../deepseek-no-think-proxy.mjs';
+import { handleUnexpectedChildExit } from './dev-process-lifecycle.mjs';
 
 const root = path.join(path.dirname(fileURLToPath(import.meta.url)), '..');
 const opsDir = path.join(root, 'ops');
@@ -52,11 +53,13 @@ function spawnChild(command, args, label, cwd = root, extraEnv = {}) {
     stdio: 'inherit',
   });
   child.on('exit', (code, signal) => {
-    if (signal) return;
-    if (code && code !== 0) {
-      console.error(`[${label}] exited with code ${code}`);
-      shutdown(code ?? 1);
-    }
+    handleUnexpectedChildExit({
+      label,
+      code,
+      signal,
+      stopping,
+      shutdown,
+    });
   });
   return child;
 }

scripts/dev-process-lifecycle.mjs

@@ -0,0 +1,16 @@
+export function handleUnexpectedChildExit({
+  label,
+  code,
+  signal,
+  stopping,
+  shutdown,
+  log = console.error,
+}) {
+  if (stopping) return false;
+
+  const detail = signal ? `signal ${signal}` : `code ${code ?? 'unknown'}`;
+  const shutdownCode = Number.isInteger(code) && code > 0 ? code : 1;
+  log(`[${label}] exited unexpectedly (${detail}); shutting down dev stack`);
+  shutdown(shutdownCode);
+  return true;
+}

scripts/dev-process-lifecycle.test.mjs

@@ -0,0 +1,47 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { handleUnexpectedChildExit } from './dev-process-lifecycle.mjs';
+
+function invokeExit({ code, signal, stopping = false }) {
+  const shutdownCodes = [];
+  const messages = [];
+  const handled = handleUnexpectedChildExit({
+    label: 'portal',
+    code,
+    signal,
+    stopping,
+    shutdown: (shutdownCode) => shutdownCodes.push(shutdownCode),
+    log: (message) => messages.push(message),
+  });
+  return { handled, shutdownCodes, messages };
+}
+
+test('clean child exit shuts down the remaining dev stack as a failure', () => {
+  const result = invokeExit({ code: 0, signal: null });
+
+  assert.equal(result.handled, true);
+  assert.deepEqual(result.shutdownCodes, [1]);
+  assert.match(result.messages[0], /code 0/);
+});
+
+test('signal exit shuts down the remaining dev stack as a failure', () => {
+  const result = invokeExit({ code: null, signal: 'SIGKILL' });
+
+  assert.equal(result.handled, true);
+  assert.deepEqual(result.shutdownCodes, [1]);
+  assert.match(result.messages[0], /signal SIGKILL/);
+});
+
+test('non-zero child exit preserves its failure code', () => {
+  const result = invokeExit({ code: 7, signal: null });
+
+  assert.deepEqual(result.shutdownCodes, [7]);
+});
+
+test('child exits during an intentional shutdown are ignored', () => {
+  const result = invokeExit({ code: 0, signal: null, stopping: true });
+
+  assert.equal(result.handled, false);
+  assert.deepEqual(result.shutdownCodes, []);
+  assert.deepEqual(result.messages, []);
+});