diff --git a/_docs/LESSONS.md b/_docs/LESSONS.md
index 7a583dc..cfedeaf 100644
--- a/_docs/LESSONS.md
+++ b/_docs/LESSONS.md
@@ -4,6 +4,12 @@ Append-only ledger of lessons learned during the project. New entries go at the
 
 ---
 
+## 2026-05-18 — When autodev rewinds N → 7 (or any earlier step) mid-session, treat the handoff as a session boundary
+
+**Trigger**: In Step 11 (Run Tests) cycle 1, the Jetson e2e gate routed the flow back to Step 7 (Implement) for AZ-618 (cross-cutting 5pt task with 12 infrastructure deps). The user repeatedly chose to continue in the same conversation. I rewound state cleanly (task spec + autodev state) but, on attempting to enter the implement skill's batch loop in the SAME conversation, found that even just investigating the 12 builder signatures consumed enough context to reach the Caution zone — writing the implementation would have hit truncation mid-batch.
+
+**What changed**: When the autodev rewinds the flow to an EARLIER step in the same conversation (Step 11 → Step 7, Step 11 → Step 9, etc.), treat the rewind itself as a session boundary, regardless of whether the flow file's Auto-Chain Rules table marks it as one. Save the bootstrap artifacts (task spec, state, dependencies-table refresh), commit them, then ask for a fresh conversation. The rewind already cost real tool calls; the destination step's batch loop deserves clean context. Document the rewind reason in `sub_step.detail` so re-entry is one-line clear.
+
 ## 2026-05-17 — Always call `getTransitionsForJiraIssue` before `transitionJiraIssue`
 
 **Trigger**: In batch 87 (autodev step 10), I transitioned AZ-436..AZ-439 with `transition.id="31"` assuming = "In Progress" from stale memory. Read-back showed all four moved to **Done** instead (id `31` in this workflow = Done; In Progress = `21`, In Testing = `32`, To Do = `11`). The mistake was caught by the tracker rule's mandatory read-back gate, fixed by re-transitioning to `21`, and confirmed via second read-back.