Security/Browser: constrain trace and download output paths to OpenClaw temp roots (#15652)

* Browser/Security: constrain trace and download output paths to temp roots

* Changelog: remove advisory ID from pre-public security note

* Browser/Security: constrain trace and download output paths to temp roots

* Changelog: remove advisory ID from pre-public security note

* test(bluebubbles): align timeout status expectation to 408

* test(discord): remove unused race-condition counter in threading test

* test(bluebubbles): align timeout status expectation to 408

src/browser/routes/path-output.ts

@@ -0,0 +1,28 @@
+import path from "node:path";
+import { resolvePreferredOpenClawTmpDir } from "../../infra/tmp-openclaw-dir.js";
+
+export const DEFAULT_BROWSER_TMP_DIR = resolvePreferredOpenClawTmpDir();
+export const DEFAULT_TRACE_DIR = DEFAULT_BROWSER_TMP_DIR;
+export const DEFAULT_DOWNLOAD_DIR = path.join(DEFAULT_BROWSER_TMP_DIR, "downloads");
+
+export function resolvePathWithinRoot(params: {
+  rootDir: string;
+  requestedPath: string;
+  scopeLabel: string;
+  defaultFileName?: string;
+}): { ok: true; path: string } | { ok: false; error: string } {
+  const root = path.resolve(params.rootDir);
+  const raw = params.requestedPath.trim();
+  if (!raw) {
+    if (!params.defaultFileName) {
+      return { ok: false, error: "path is required" };
+    }
+    return { ok: true, path: path.join(root, params.defaultFileName) };
+  }
+  const resolved = path.resolve(root, raw);
+  const rel = path.relative(root, resolved);
+  if (!rel || rel.startsWith("..") || path.isAbsolute(rel)) {
+    return { ok: false, error: `Invalid path: must stay within ${params.scopeLabel}` };
+  }
+  return { ok: true, path: resolved };
+}