refactor: type reward_type columns as UserGoodsType enum

Replace bare `int RewardType` on 12 catalog/reward entities and GrantedReward
with the existing UserGoodsType enum. Verified against the decompiled client:
every wire reward_type decodes through the single Wizard.UserGoods.Type enum, so
one enum is correct across all endpoint families (item_type is a separate
Item.Type axis, left untouched). EF stores the enum as the same int column, so
there is no migration.

- Importers cast seed int -> UserGoodsType at the ingest boundary.
- New GrantedReward.ToRewardList() extension replaces 8 copy-pasted
  GrantedReward -> RewardListEntry projections.
- Fix 3 .ToString() sites that would otherwise emit enum names ("Crystal")
  instead of the int wire value ("2").
- Wire DTOs keep int; the enum is widened to int at the wire boundary only.

Build green; 962/962 tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Services/ArenaTwoPickService.cs

@@ -301,7 +301,7 @@ public class ArenaTwoPickService : IArenaTwoPickService
         // Pre-load item_type for any Item-typed reward so we can populate it on the
         // per-grant delta entries. Currencies don't need a lookup (item_type stays 0).
         var itemRewardIds = rewardRows
-            .Where(r => r.RewardType == (int)UserGoodsType.Item)
+            .Where(r => r.RewardType == UserGoodsType.Item)
             .Select(r => (int)r.RewardId)
             .Distinct()
             .ToList();
@@ -325,10 +325,10 @@ public class ArenaTwoPickService : IArenaTwoPickService
             // Skip when the rolled outcome is "nothing" (RewardNum == 0).
             if (pick.RewardNum <= 0) continue;
 
-            await tx.GrantAsync((UserGoodsType)pick.RewardType, pick.RewardId, pick.RewardNum);
+            await tx.GrantAsync(pick.RewardType, pick.RewardId, pick.RewardNum);
             deltas.Add(new TwoPickRewardReceivedDto
             {
-                RewardType     = pick.RewardType,
+                RewardType     = (int)pick.RewardType,
                 RewardDetailId = pick.RewardId,
                 RewardCount    = pick.RewardNum,
                 ItemType       = itemTypeById.TryGetValue((int)pick.RewardId, out var t) ? t : 0,
@@ -339,7 +339,7 @@ public class ArenaTwoPickService : IArenaTwoPickService
         var result = await tx.CommitAsync();
 
         var postStates = result.RewardList
-            .Select(g => new RewardEntryDto { RewardType = g.RewardType, RewardId = g.RewardId, RewardNum = g.RewardNum })
+            .Select(g => new RewardEntryDto { RewardType = (int)g.RewardType, RewardId = g.RewardId, RewardNum = g.RewardNum })
             .ToList();
 
         await _runs.DeleteAsync(viewerId);