Context ring no longer warns before the window limit — session died at 'Prompt is too long' with no prior warning

Summary

The context-usage ring at the bottom of a session used to turn yellow at roughly 75% of the context window. In current builds it no longer does — sessions now run under a large total token budget with automatic context summarization, and the ring tracks that budget instead of the actual context window. Result: no early warning at all before the hard limit.

What happened

A long working session died mid-turn with "Prompt is too long" — no yellow indicator, no warning of any kind beforehand. Automatic compaction did not kick in (it can't mid-turn, when a single prompt — conversation plus a large paste — exceeds the window), so the first and only signal was the session becoming unusable. It could no longer even write a handoff for a successor session; the work state had to be reconstructed from the transcript by a new session.

autoCompactEnabled / autoCompactWindow control when compaction runs, not the indicator, and did not prevent this.

What I'm asking for

Restore a visible warning tied to the actual context window (the old yellow-at-~75% behavior), or a setting to opt back into it. The total-budget display is fine as a default, but the hard per-prompt window still exists and users get zero warning before hitting it.

Environment

• Claude Code desktop app, Windows 11 Enterprise 10.0.26200
• Current build as of 2026-09-02