fix: protocolTimeout for heavy pages + attach-mode arg cleanup

Two reliability fixes for symptoms hit on real workloads:

1. Heavy pages (e.g. Studio module dev bundles >100MB) cannot ack
   `Network.enable` and other auto-attached domain calls within
   puppeteer's default 180s timeout. Once it fires, the CDP connection
   is marked dead and every subsequent call throws — only daemon
   restart recovers. Bump `protocolTimeout` to 10min for both
   `puppeteer.connect` and `puppeteer.launch`, env-overridable via
   `BRAVE_DEVTOOLS_PROTOCOL_TIMEOUT_MS`.

2. `start --browserUrl X` was emitting `--browser-url X --headless
   --isolated` in the daemon args because the spawn-mode defaults
   (`headless: true`, `isolated: true`) were applied unconditionally
   after yargs parsing. The runtime resolver ignored them under attach
   mode but `status` showed misleading args, and the silent fallthrough
   would become a real bug if the resolver order ever changed. Detect
   attach mode (`browserUrl` / `wsEndpoint` / `autoConnect`) and strip
   spawn-only flags before serializing.

Smoke-tested both modes: attach now reports
`args=[--browser-url X, --category-..., ...]` and spawn still gets
`[--headless, --isolated, ...]`.

Co-authored-by: Claude <noreply@anthropic.com>

Author: triuzzi

src/bin/brave-devtools.ts

@@ -97,12 +97,29 @@ y.command(
     if (isDaemonRunning(argv.sessionId)) {
       await stopDaemon(argv.sessionId);
     }
-    // Defaults but we do not want to affect the yargs conflict resolution.
-    if (argv.isolated === undefined && argv.userDataDir === undefined) {
-      argv.isolated = true;
-    }
-    if (argv.headless === undefined) {
-      argv.headless = true;
+    // Defaults only apply to *spawn* mode. Skip / clear them when
+    // attaching to an existing browser, otherwise `status` shows
+    // misleading args like `--browserUrl X --headless --isolated`
+    // together (the runtime ignores headless/isolated under attach,
+    // but storing them anyway is a footgun if the resolver order ever
+    // changes — and confuses anyone reading `status` output).
+    const isAttachMode =
+      argv.browserUrl !== undefined ||
+      argv.wsEndpoint !== undefined ||
+      argv.autoConnect === true;
+    if (isAttachMode) {
+      // Strip spawn-mode flags so serializeArgs doesn't emit them.
+      // Headless has `default: true` in the CLI override, so this is
+      // necessary even when the user didn't pass `--headless`.
+      delete argv.headless;
+      delete argv.isolated;
+    } else {
+      if (argv.isolated === undefined && argv.userDataDir === undefined) {
+        argv.isolated = true;
+      }
+      if (argv.headless === undefined) {
+        argv.headless = true;
+      }
     }
     const args = serializeArgs(cliOptions, argv);
     await start(args, argv.sessionId);

src/browser.ts

@@ -21,6 +21,17 @@ let browser: Browser | undefined;
 
 export type Channel = 'release' | 'beta' | 'nightly' | 'dev';
 
+// Heavy pages (e.g. Studio module dev bundles >100MB) cannot ack
+// `Network.enable` and other auto-attached domain calls within
+// puppeteer's default 180s. Once that fires, the CDP connection is
+// marked dead and every subsequent call throws — only daemon restart
+// recovers. Bumping the ceiling to 10min covers realistic loads;
+// override via env for power users.
+const PROTOCOL_TIMEOUT_MS = parseInt(
+  process.env.BRAVE_DEVTOOLS_PROTOCOL_TIMEOUT_MS ?? '600000',
+  10,
+);
+
 function makeTargetFilter(enableExtensions = false) {
   const ignoredPrefixes = new Set([
     'chrome://',
@@ -189,6 +200,7 @@ export async function ensureBrowserConnected(options: {
     targetFilter: makeTargetFilter(enableExtensions),
     defaultViewport: null,
     handleDevToolsAsPage: true,
+    protocolTimeout: PROTOCOL_TIMEOUT_MS,
   };
 
   let autoConnect = false;
@@ -340,6 +352,7 @@ export async function launch(options: McpLaunchOptions): Promise<Browser> {
       acceptInsecureCerts: options.acceptInsecureCerts,
       handleDevToolsAsPage: true,
       enableExtensions: options.enableExtensions,
+      protocolTimeout: PROTOCOL_TIMEOUT_MS,
     });
     if (options.logFile) {
       browser.process()?.stderr?.pipe(options.logFile);