fix(pool): a Codex ChatGPT pool pane runs on the login placed for it

Codex >= 0.164 hands a plain TUI (no -c override) to the CODEX_HOME's
shared app-server daemon, which outlives every TUI and keeps the login it
started with. A ChatGPT pool account written into a member's auth.json
therefore reached no pane while their daemon still ran on the previous
login (reproduced on 0.164.0: the daemon kept sending the old key, a
--no-daemon TUI sent the new one). Such a pane now runs `codex
--no-daemon`, only when that binary's --help lists the flag (probed once
per path/size/mtime), so an older Codex still starts.

server/lib/codex-pool.js

@@ -19,7 +19,9 @@
  *     home AgentHub placed that account in, never dated in the future, and
  *     only when its id_token names the same account (`mayCopyBack`); the 2026-10-08
  *     spike showed an old refresh token still refreshes, so panes sharing an
- *     account do not log each other out.
+ *     account do not log each other out. Such a pane runs `--no-daemon`
+ *     (when its Codex has the flag): the home's shared app-server daemon
+ *     would keep serving the login it started with.
  *
  * Records live in `<CLAUDE_HOME>/agenthub-codex-accounts/<name>.json` (dir
  * 0700, file 0600); no route returns a key or a token.
@@ -424,6 +426,46 @@ function liveInHome(name, member) {
     });
 }
 
+// Codex ≥ 0.164 hands a plain TUI (no `-c` override) to the CODEX_HOME's shared
+// app-server daemon, which outlives every TUI and keeps the login it started
+// with — so a ChatGPT login placed in the home reached no pane while the
+// member's daemon ran on the previous one (reproduced on 0.164.0). A pool pane
+// runs its own app server instead. An older Codex has neither the daemon nor
+// the flag (it would refuse to start), so the flag goes only to a binary whose
+// --help lists it: probed once per binary (path, size, mtime).
+const noDaemonCache = new Map();
+
+function noDaemonArgv(member) {
+  const bin =
+    process.env.AGENTHUB_CODEX_BIN ||
+    (member
+      ? require("./shared-tools").sharedPath("codex")
+      : require("./ai-tools").detect("codex").path);
+  if (!bin) return [];
+  let key;
+  try {
+    const st = fs.statSync(bin);
+    key = `${fs.realpathSync(bin)}:${st.size}:${st.mtimeMs}`;
+  } catch {
+    return [];
+  }
+  if (!noDaemonCache.has(key)) {
+    let help = "";
+    try {
+      help = require("node:child_process").execFileSync(bin, ["--help"], {
+        encoding: "utf8",
+        timeout: 5000,
+        stdio: ["ignore", "pipe", "ignore"],
+        windowsHide: true,
+      });
+    } catch {
+      /* no answer: leave the flag out, as before */
+    }
+    noDaemonCache.set(key, /--no-daemon\b/.test(help));
+  }
+  return noDaemonCache.get(key) ? ["--no-daemon"] : [];
+}
+
 /** `{name, kind}` of the account a new Codex pane would get, or null. */
 function pickAccount(member = null, ownerId = null) {
   const a = pick(member, ownerId);
@@ -449,7 +491,7 @@ function forSpawn(member = null, ownerId = null) {
   }
   return {
     name: a.name,
-    argv: [],
+    argv: noDaemonArgv(member),
     env: {},
     place: () => {
       syncHome(member.home); // a live pane may hold a newer login than ours