Show remaining usage limit in Codex app chat

Feature request

Please bring back a visible usage / remaining limit indicator directly under the Codex app chat, like it was before.

Right now the limit is too opaque: users can run into usage limits while actively working without enough warning, and the remaining quota/reset time is not visible in the place where the work is happening. That makes Codex harder to trust for longer development sessions.

Expected behavior:

• Show current usage or remaining messages/percentage in the Codex app/chat UI.
• Show reset time for relevant windows.
• Keep it visible near the chat/status area without requiring a separate settings page or command.

Related but different from #15281, which focuses on CLI /status//statusline. This request is specifically for the Codex app chat UI.