Distillation

Date: Sep 17, 2026

• 🔴 (08:39) User established the ownership-safety invariant “never fails interrupted tools after ownership changes,” tested in packages/core/test/session-runner.test.ts:845.
• 🔴 (08:39) User established the finalization-safety invariant “never marks a failed Step safe while a sibling tool finalizer is active,” tested in packages/core/test/session-runner.test.ts:3788.
• 🟡 (08:39) Additional recovery/finalization coverage identified in packages/core/test/session-runner.test.ts: “retains the claim after user decline until runner finalizers finish” at line 3591; “settles cancellation when interrupted tool publication defects” at line 3906; “settles cancellation after Step failure while a local tool is active” at line 3952; “settles cancellation when Step start notification is interrupted” at line 4001; and “retains the claim after Step interruption until runner finalizers finish” at line 4055.
• 🟡 (08:39) Snapshot failure coverage identified in packages/core/test/session-runner.test.ts:1060: “fails gracefully when a stored context snapshot cannot be decoded”; the malformed fixture sets snapshot: { invalid: { value: "bad" } } at line 1070.