fix: 브라우저 재시작 process 경계를 통일한다

재시작 전용 runner도 POSIX 독립 process group으로 실행하고 비 detached 호출에는 종료 fallback을 둔다.
같은 profile을 쓰는 다음 phase가 이전 Chrome의 lock에 막히지 않도록 구조 계약을 고정한다.
검증: npm test, npm run test:web-computer

Author: eddmpython

scripts/browserControl/browserLauncher.mjs

@@ -81,6 +81,7 @@ export function killBrowserProcess(proc, profileDir = null) {
     try { process.kill(-proc.pid, "SIGKILL"); }
     catch (error) {
       if (error?.code !== "ESRCH") throw error;
+      if (proc.exitCode === null) proc.kill("SIGKILL");
     }
   }
   if (process.platform === "win32" && profileDir) {

tests/browser/run.mjs

@@ -132,7 +132,10 @@ function launch(url, phase) {
   console.log(`${phase === 1 ? "pyproc 브라우저 게이트" : `\n브라우저 재시작 phase ${phase}`}\n  browser: ${browser}\n  url:     ${url}\n`);
   launcherExit = null;
   const spawnedAt = Date.now();
-  const child = spawn(browser, [...headlessArgs(currentProfile), url], { stdio: "ignore" });
+  const child = spawn(browser, [...headlessArgs(currentProfile), url], {
+    stdio: "ignore",
+    detached: process.platform !== "win32",
+  });
   child.on("exit", (code, signal) => { launcherExit = { code, signal, afterMs: Date.now() - spawnedAt }; });
   return child;
 }

tests/contracts/moduleBoundaries.mjs

@@ -112,7 +112,7 @@ function verifyReleaseVersionSurfaces(packageJson) {
   }
 }
 
-function verifyBrowserLauncherCleanup(source) {
+function verifyBrowserLauncherCleanup(source, browserRunner) {
   for (const required of [
     "PROFILE_ABSENCE_STABILITY_MS",
     'process.kill(-proc.pid, "SIGKILL")',
@@ -123,6 +123,9 @@ function verifyBrowserLauncherCleanup(source) {
   if (!/killBrowserProcess\(proc, profile\);\s*removeBrowserProfile\(profile\);/u.test(source)) {
     throw new Error("browser profile을 process tree 종료보다 먼저 지운다");
   }
+  if (!browserRunner.includes('detached: process.platform !== "win32"')) {
+    throw new Error("browser restart runner가 POSIX process group 경계를 만들지 않는다");
+  }
 }
 
 export function assertModuleBoundaries() {
@@ -144,7 +147,10 @@ export function assertModuleBoundaries() {
 
   const goldenPage = readFileSync(join(ROOT, "tests", "browser", "goldenWorkflow.html"), "utf8");
   const packageJson = JSON.parse(readFileSync(join(ROOT, "package.json"), "utf8"));
-  verifyBrowserLauncherCleanup(readFileSync(join(ROOT, "scripts", "browserControl", "browserLauncher.mjs"), "utf8"));
+  verifyBrowserLauncherCleanup(
+    readFileSync(join(ROOT, "scripts", "browserControl", "browserLauncher.mjs"), "utf8"),
+    readFileSync(join(ROOT, "tests", "browser", "run.mjs"), "utf8"),
+  );
   verifyReleaseVersionSurfaces(packageJson);
   verifyGoldenWorkflowImports(goldenPage, packageJson);
   // 음성 fixture: 공개 specifier는 그대로여도 import map이 package export target에서 표류하면