Distillation

Date: Sep 16, 2026

• 🟡 (11:13) Gateway streaming tests were expanded with test.each coverage for 4 principal-provider failure combinations: 1. response.failed with status failed, 2. response.failed with status cancelled, 3. response.done with status failed, 4. response.done with status cancelled.
• 🟡 (11:13) The new failure-sanitization tests use PUBLIC_GATEWAY_ERROR, include per-case private sentinel text via private-sparse-${terminalEvent}-${terminalStatus}, and verify failed accounting completion receives rawOutputItems: [].
• 🟡 (11:13) Additional visible gateway test fixtures cover trusted principal failure (resp_trusted_principal_failure), usage { input_tokens: 7, output_tokens: 3 }, atomic terminal handling (resp_atomic_terminal), and atomic output/reference items including msg_atomic_reference.