diff --git a/docs/testing/wine-proton-phases.md b/docs/testing/wine-proton-phases.md
index 234e756..fb41963 100644
--- a/docs/testing/wine-proton-phases.md
+++ b/docs/testing/wine-proton-phases.md
@@ -444,6 +444,16 @@ above. Its root cause is already localized to wine-access
 (`edit_hook.c` subclass persistence plus ungated text-event
 presentation in `main.cpp`).
 
+Session-model amendment, 2026-11-01: the maintainer elected to
+conduct Phase 4 in the master/coordinator session
+(`still-enceladus`) rather than a fresh phase session. The
+maintainer runs the live corpus and reports results; the master
+session records them in the contract and runs automated checks.
+No implementation is planned in this phase; if a regression needs
+code, a fresh narrow defect session is spawned on the relevant
+branch at that point, and the master session remains
+coordinator/recorder rather than implementer.
+
 Maintainer disposition, 2026-11-01: **deferred; do not fix in
 Phase 4 and do not open a wine-access defect branch for it.**
 Rationale: tearing down helper/subclass state early risks