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/Controllers/BattlePassController.cs

@@ -64,7 +64,7 @@ public class BattlePassController : SVSimController
                 BattlePassRewardList = outcome.AchievedRewards
                     .Select(g => new BattlePassReceivedRewardDto
                     {
-                        RewardType = g.RewardType,
+                        RewardType = (int)g.RewardType,
                         RewardDetailId = g.RewardId,
                         RewardNumber = g.RewardNum,
                     }).ToList(),
@@ -72,7 +72,7 @@ public class BattlePassController : SVSimController
             RewardList = outcome.PostStateTotals
                 .Select(g => new BattlePassRewardListEntryDto
                 {
-                    RewardType = g.RewardType,
+                    RewardType = (int)g.RewardType,
                     RewardId = g.RewardId,
                     RewardNum = g.RewardNum,
                 }).ToList(),