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/PuzzleController.cs

@@ -109,7 +109,7 @@ public class PuzzleController : SVSimController
             RewardList = new List<PuzzleMissionRewardResponse>
             {
                 new() {
-                    RewardType = s.Mission.RewardType,
+                    RewardType = (int)s.Mission.RewardType,
                     RewardDetailId = s.Mission.RewardDetailId,
                     RewardNumber = s.Mission.RewardNumber,
                 },
@@ -182,7 +182,7 @@ public class PuzzleController : SVSimController
                 try
                 {
                     granted = await tx.GrantAsync(
-                        (UserGoodsType)status.Mission.RewardType,
+                        status.Mission.RewardType,
                         status.Mission.RewardDetailId,
                         status.Mission.RewardNumber);
                 }
@@ -200,7 +200,7 @@ public class PuzzleController : SVSimController
                 });
                 response.AchievedInfo.AchievedMissionRewardList.Add(new PuzzleAchievedMissionReward
                 {
-                    MissionRewardType = status.Mission.RewardType,
+                    MissionRewardType = (int)status.Mission.RewardType,
                     MissionRewardDetailId = status.Mission.RewardDetailId,
                     MissionRewardNumber = status.Mission.RewardNumber,
                 });
@@ -208,7 +208,7 @@ public class PuzzleController : SVSimController
                 {
                     response.RewardList.Add(new TreasureRewardResponse
                     {
-                        RewardType = g.RewardType,
+                        RewardType = (int)g.RewardType,
                         RewardId = g.RewardId,
                         RewardNum = g.RewardNum,
                     });