diff --git a/09 - Audits/Activity Log.md b/09 - Audits/Activity Log.md
index 2e90ca1..07ceac3 100644
--- a/09 - Audits/Activity Log.md	
+++ b/09 - Audits/Activity Log.md	
@@ -1307,4 +1307,18 @@ delivered/confirming → 5, seller_paid/completed → 6. Removed the unreliable
 
 ---
 
+### 2026-06-04 — backend v2.8.77 — seller can't ship: delivery 403 (uuid↔ObjectId seam)
+
+The selected seller got HTTP 403 on PUT /marketplace/purchase-requests/:id/delivery
+(«تأیید ارسال کالا») for a paid shop request. The auth compared the seller's
+session id (legacy ObjectId e0527…) against the selected offer's sellerId, which a
+TEMPLATE-created offer stores as a PG uuid (669c0dac…) → never equal → 403. Added a
+`sameUser(a,b)` helper that resolves both ids via the user repo (accepts either
+format) and compares every id form (_id/id/pgId/legacyObjectId). Applied to
+updateDeliveryInfo, verifyDeliveryCode, and the delivery-code-status buyer/seller
+gate. (Buyer step labels already matched the web — no change.)
+**Verification:** backend tsc clean.
+
+---
+
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