diff --git a/docs/ISSUES.md b/docs/ISSUES.md
index e76754b5..ab510ba1 100644
--- a/docs/ISSUES.md
+++ b/docs/ISSUES.md
@@ -24,6 +24,32 @@ What does NOT go here:
 - Every session: scan OPEN issues at start; promote/close anything we touched during the session before ending.
 - Promoting to a Phase: mark as `DONE (promoted to Phase X)` + commit SHA where the Phase entry landed.
 
+## #350 — Render-shadow ledger overflow after 2h42m: lifetime int counters in a never-reset accumulator
+
+**Status:** FIXED IN TREE 2026-08-08 (pending clean-room + landing).
+**Evidence:** `vendor-buy-gate.log` ~1606 — checked OverflowException in
+`RenderSceneShadowRuntime.Add` from `UpdateFrameOrchestrator.Tick`, exit 82,
+2h42m into a SINGLE world generation (login 20:28 -> crash 23:10, one
+`[world-reveal] generation=1`, no portal).
+
+**Mechanism (investigated, vendor coupling REFUTED):**
+`_cumulativeApply` sums nine int fields once per tick for the lifetime of a
+world generation and is never reset in place (production has zero Clear()
+call sites; only generation replacement constructs a fresh runtime).
+`SynchronizeActiveSources` feeds per-entity churn from TWO call sites per
+frame; at uncapped frame rates a long session's ordinary churn crosses
+int.MaxValue. Introduced `0eb66485` (2026-07-24) with the class's OTHER
+lifetime counters already ulong/long — only these nine were undersized.
+The vendor materializer was exonerated by routing analysis: shop-item
+Ingest/Remove reaches inventory deltas only, never the render journal;
+the correlation was that buy-gate testing produced the first multi-hour
+single-generation soak.
+
+**Fix:** widen `RenderDeltaApplyResult`'s nine fields to long (the
+per-tick builder stays int and widens implicitly); arithmetic stays
+checked. No clamp, no reset-behavior change — the counters are
+legitimately unbounded lifetime telemetry that was simply undersized.
+
 ## #348 — Render-loop death by Win32 cursor-handle exhaustion: Silk recreates the native cursor on every alternation
 
 **Status:** FIX IN TREE (2026-08-08) pending the vendor-gate relaunch.
diff --git a/src/AcDream.App/Rendering/Scene/RenderSceneContracts.cs b/src/AcDream.App/Rendering/Scene/RenderSceneContracts.cs
index 057d1fe7..e3450ce2 100644
--- a/src/AcDream.App/Rendering/Scene/RenderSceneContracts.cs
+++ b/src/AcDream.App/Rendering/Scene/RenderSceneContracts.cs
@@ -401,18 +401,23 @@ internal readonly record struct RenderSceneIndexCounts(
         };
 }
 
+// #350: these counters accumulate for the LIFETIME of a world generation
+// (RenderSceneShadowRuntime._cumulativeApply is never reset in place), so
+// they are 64-bit like the class's other lifetime counters — a 2h42m
+// single-generation session overflowed the original int through ordinary
+// per-tick churn. The arithmetic stays checked.
 internal readonly record struct RenderDeltaApplyResult(
-    int Applied,
-    int Registered,
-    int Updated,
-    int Replaced,
-    int Unregistered,
-    int RejectedGeneration,
-    int RejectedOutOfOrderSequence,
-    int RejectedStaleIncarnation,
-    int RejectedMissing)
+    long Applied,
+    long Registered,
+    long Updated,
+    long Replaced,
+    long Unregistered,
+    long RejectedGeneration,
+    long RejectedOutOfOrderSequence,
+    long RejectedStaleIncarnation,
+    long RejectedMissing)
 {
-    public int Rejected =>
+    public long Rejected =>
         RejectedGeneration
         + RejectedOutOfOrderSequence
         + RejectedStaleIncarnation