fix(render): #350 — the shadow ledger's lifetime counters are 64-bit; the 2h42m overflow is closed

RenderDeltaApplyResult's nine counters accumulate for the lifetime of
a world generation (the cumulative sum is never reset in place) yet
were int where every sibling lifetime counter in the same class was
already ulong/long. A 2h42m single-generation session (login to crash
with zero portals) overflowed one through ordinary per-tick churn from
SynchronizeActiveSources' two call sites per frame. Introduced
0eb66485 (2026-07-24); first reached by the vendor buy gate because
parking at a shop for hours produced the project's first multi-hour
unbroken generation. The vendor materializer was exonerated by routing
analysis (shop-item Ingest/Remove reaches inventory deltas only, never
the render journal).

Widened to long; the per-tick builder stays int and widens implicitly;
the arithmetic stays checked. All 68 render-shadow tests green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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