[Bug] Context window exceeding 200k limit with Sonnet-4.6 causes unrecoverable session state

Bug Description
While working on a task, Claude Code with Sonnet-4.6 model somehow exceeded 200k context limit and failed with "API Error: Usage credits required for 1M context". /compact now fails with the same error. The session is unusable.

Environment Info

• Platform: linux
• Terminal: WezTerm
• Version: 2.1.156
• Feedback ID: 2029eeda-3313-44b4-b8d4-cd1428fb3b3b

Errors

[{"error":"Error: Error during compaction: API Error: Usage credits required for 1M context · run /usage-credits to turn them on, or /model to switch to standard context\n    at Jn_ (/$bunfs/root/src/entrypoints/cli.js:7740:1645)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-29T16:51:14.452Z"}]