Auto-continue after usage-limit reset (2.1.234+) doesn't fire in a detached tmux session

What's Wrong?

Claude Code 2.1.234 added: "Claude Code now continues your session automatically when a claude.ai usage limit resets" (on by default, /config → "Continue automatically at usage limit"). This does not fire for a session running inside a detached tmux pane — i.e. the process is alive and the pane exists, but no client has tmux attach-ed to it.

Steps to Reproduce

1. Run claude inside a tmux session kept alive by a systemd --user service (ExecStart=tmux new-session ...), with nobody attached to the tmux client.
2. Let the session hit its usage limit mid-task.
3. Wait past the printed reset time.
4. Observe: the pane still shows the "You've hit your session limit · resets HH:MM" banner and an idle prompt, hours after reset.

What I checked before filing

• Reset time had passed by 13+ hours — not a timing/clock issue.
• Underlying process confirmed alive and previously active (ps showed real elapsed/CPU time, not hung or crashed).
• Sent input directly into the pane via tmux send-keys (a no-op keypress, then a character+backspace) to rule out "only rechecks on next render" — no change, banner persisted identically.
• claude --version → 2.1.236 (newer than the 2.1.234 floor; already apt's latest candidate).
• No override in settings.json — default (on) applies.

What Should Happen

Per the 2.1.234 changelog entry, the session should resume on its own once the limit resets, regardless of whether a tmux client is attached.

Suspected Cause

The resume check may be gated on an attached-client render/focus event rather than a real background timer, so a detached-but-alive pty never re-triggers it.

Environment

• Claude Code 2.1.236, installed via the apt package on Raspberry Pi (Debian, arm64)
• Session launched as claude --name X --resume <session-id> inside tmux new-session, itself started by a systemd --user unit
• No client ever attached to the tmux session (headless, managed via Claude Code's own Remote Control instead)