fix(gift): drop RowVersion (SQLite incompatible) + restore wire reward_type map

[Timestamp] byte[] doesn't work under SQLite (the test backend) — EF
expects the DB to populate it on insert, but SQLite has no equivalent
of Postgres's xmin. The WHERE Status = Unclaimed filter plus
IInventoryService's viewer-level concurrency is the practical defense;
RowVersion was only a backstop. Regenerated the migration without the
RowVersion column.

Wire reward_type on the gift endpoint uses a gift-specific scheme that
diverges from UserGoodsType for currencies: wire 1 = Crystal (enum=2),
wire 9 = Rupy (enum=9), wire 4 = Item (enum=4). A naked cast resolves
wire 1 to UserGoodsType.RedEther and silently grants the wrong wallet
— restored the explicit WireRewardTypeToUserGoodsType map from the old
tutorial controller.

Retrofits existing GiftControllerTests to call SeedTutorialPresentsAsync
on the new helper (RegisterViewer doesn't auto-seed; only the prod
signup path does). All 7 existing tests pass.

SVSim.EmulatedEntrypoint/Controllers/GiftController.cs

@@ -84,8 +84,12 @@ public class GiftController : SVSimController
         {
             if (state == 1)
             {
+                // Wire reward_type on the gift endpoint follows a gift-specific scheme that
+                // diverges from UserGoodsType for currencies: wire "1" means Crystal (enum=2),
+                // wire "9" means Rupy (enum=9), wire "4" means Item (enum=4). A naked cast would
+                // resolve wire 1 -> UserGoodsType.RedEther and silently grant the wrong wallet.
                 var granted = await tx.GrantAsync(
-                    (UserGoodsType)p.RewardType,
+                    WireRewardTypeToUserGoodsType(p.RewardType),
                     p.RewardDetailId,
                     (int)p.RewardCount);
 
@@ -161,6 +165,14 @@ public class GiftController : SVSimController
         };
     }
 
+    private static UserGoodsType WireRewardTypeToUserGoodsType(int wireType) => wireType switch
+    {
+        1 => UserGoodsType.Crystal,
+        4 => UserGoodsType.Item,
+        9 => UserGoodsType.Rupy,
+        _ => throw new InvalidOperationException($"Unmapped gift wire reward_type {wireType}"),
+    };
+
     private async Task<(List<ViewerPresent> Unclaimed, List<ViewerPresent> History)> ReadTopWindowAsync(
         long viewerId, int page)
     {