Reproduction steps

1. Run the zed binary from a recent build
2. Watch an ERROR logged:
   ERROR [crates/zeta/src/sweep_ai.rs:36] No SWEEP_AI_TOKEN environment variable set

Current vs. Expected behavior

No error should be logged for an optional feature that the user hasn't enabled. The default edit prediction model is Zeta2, not Sweep, so the missing token is expected for most users.

If applicable, attach your Zed log file to this issue.

If applicable, provide details about your model provider

No response

Zed version and system specs

Zed Dev 0.215.0+8d0bf516777fed120d7d715a17e28746bc0ac583
macOS Tahoe 26.1
M3 Max Chip