Background sessions now keep their sign-in profile

What

A background session is one started with --bg, which runs on its own while you do other things. A small helper program called a daemon starts and restarts these sessions. Background sessions now remember which account they were signed in with:

• Saved sign-in: starting or restarting a background session now records a sign-in pin, a note of which sign-in to use, and ANTHROPIC_PROFILE in the session's environment. Before, the settings were copied from the current environment only.
• Outdated daemon: a daemon that does not keep the profile is detected and treated as outdated or unreachable.
• Older sessions: a session saved without its sign-in refuses to restart with error code sign_in_unknown. The message says the session was saved by an older version, and that to continue it you should run claude --resume as you started it: same launcher, or same ANTHROPIC_PROFILE.
• New failure reasons: starting a background session can now fail with daemon_outdated or credential_unavailable. These take the same path as gate_blocked and cwd_gone. Before, only those two did.
• Settings files: if a --settings file overrides the credential or profile, the session falls back to pin none.

Why

If you use more than one Anthropic profile, background sessions keep using the account they started with. When that cannot be guaranteed, you get a specific refusal instead of the session quietly running under another account.