Add CDP-only debug mode

scripts/debug-chatgpt-share.mjs

@@ -10,6 +10,7 @@ const sourceUrl = process.argv[2];
 const holdMs = Number(process.env.DEBUG_HOLD_MS || "900000");
 const port = Number(process.env.DEBUG_PORT || "9222");
 const proxyPort = process.env.DEBUG_PROXY_PORT ? Number(process.env.DEBUG_PROXY_PORT) : null;
+const cdpOnly = process.env.DEBUG_CDP_ONLY === "1";
 
 if (!sourceUrl) {
   console.error("usage: node scripts/debug-chatgpt-share.mjs <chatgpt-share-url>");
@@ -67,7 +68,7 @@ browserProcess = spawn(executablePath, [
   "--remote-debugging-address=0.0.0.0",
   `--remote-debugging-port=${port}`,
   `--user-data-dir=${userDataDir}`,
-  "about:blank"
+  cdpOnly ? sourceUrl : "about:blank"
 ], {
   stdio: ["ignore", "pipe", "pipe"]
 });
@@ -104,6 +105,13 @@ if (proxyPort) {
   console.log(`[${now()}] DevTools proxy: 0.0.0.0:${proxyPort} -> 127.0.0.1:${port}`);
 }
 
+if (cdpOnly) {
+  console.log(`[${now()}] CDP-only mode; holding browser for ${Math.round(holdMs / 1000)}s.`);
+  await new Promise((resolve) => setTimeout(resolve, holdMs));
+  await close();
+  process.exit(0);
+}
+
 browser = await chromium.connectOverCDP(`http://127.0.0.1:${port}`);
 
 context = await browser.newContext({