CLAUDE_CODE_AUTO_MODE_SERVER now forces server review of auto mode on or off for first-party users too

What

CLAUDE_CODE_AUTO_MODE_SERVER is an environment variable (a setting read from your shell when Claude Code starts) that decides whether auto mode asks the server to review its actions instead of making its own classifier requests. It used to be read only for third-party providers. It is now also read on the first-party path, meaning a direct connection to Anthropic.

• Set to a false value, it forces server review off.
• Set to a true value, it turns server review on (internally the "arbiter" mode) without needing the tengu_smooth_chipmunk flag. It still requires the tengu_iridescent_crystal flag to be off and that the server has not refused the third-party classifier.
• Left unset, the tengu_smooth_chipmunk flag decides as before, and its built-in default is off. A build-time override hook sits in that fallback but does nothing in this build.
• The variable is now read once into userServerClassifierSwitch, which is empty when the variable is unset and otherwise true or false, so the code can tell "not set" apart from an explicit choice.
• For third-party providers the result is unchanged: thirdPartyServerClassifierEnabled follows the variable when it is set, and otherwise is on unless CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS is set without CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST.

Why

First-party users can opt in to server-side review ahead of the rollout flag, or opt out of it, with a single environment variable, whatever the remote flag says.