refactor(codex): 將 app-server 取帳號邏輯抽到 app/codex_account.py

把原本內嵌在 action.yml heredoc 的 python 抽成獨立檔 app/codex_account.py，
action 改以 $GITHUB_ACTION_PATH/app/codex_account.py 呼叫，便於閱讀與維護。

app/codex_account.py

@@ -0,0 +1,57 @@
+"""透過 codex app-server 的 JSON-RPC account/read 取得目前登入帳號的 email。
+
+這是 TUI `/status` Account 欄位的程式化來源，不解析本地 OAuth token，
+而是由 codex 自身回報登入帳號。將 email 印到 stdout（取不到時印空字串）。
+"""
+
+import json
+import subprocess
+import time
+
+
+def read_account_email(timeout_seconds: float = 25.0) -> str:
+    process = subprocess.Popen(
+        ["codex", "app-server"],
+        stdin=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.DEVNULL,
+        text=True,
+        bufsize=1,
+    )
+
+    def send(obj):
+        process.stdin.write(json.dumps(obj) + "\n")
+        process.stdin.flush()
+
+    send({
+        "jsonrpc": "2.0",
+        "id": 1,
+        "method": "initialize",
+        "params": {"clientInfo": {"name": "ci", "version": "1.0"}},
+    })
+    send({"jsonrpc": "2.0", "method": "initialized", "params": {}})
+    send({"jsonrpc": "2.0", "id": 2, "method": "account/read", "params": {}})
+
+    email = ""
+    deadline = time.time() + timeout_seconds
+    try:
+        while time.time() < deadline:
+            line = process.stdout.readline()
+            if not line:
+                break
+            try:
+                message = json.loads(line)
+            except ValueError:
+                continue
+            if message.get("id") == 2:
+                account = (message.get("result") or {}).get("account") or {}
+                email = account.get("email") or ""
+                break
+    finally:
+        process.terminate()
+
+    return email
+
+
+if __name__ == "__main__":
+    print(read_account_email())