feat(mission): wire class_level_up emits from every XP-granting controller

Every _xp.GrantAsync callsite now conditionally emits class_level_up:{class}
when the returned BattleXpGrantResult.LeveledUp is true. Six callsites total:

- PracticeController.Finish
- RankBattleController.FinishInternal
- FreeBattleController.Finish
- ArenaTwoPickBattleController.Finish (LeveledUp + ClassId routed via
  BattleFinishResultDto — controller-side signals, not on wire)
- ArenaColosseumBattleController (missed in the original wire-up survey;
  colosseum-battle XP now also fires the level-up event when applicable)
- StoryController.Finish (LeveledUp + ClassId routed via new
  StoryFinishOutcome wrapper, mirroring the TK2 RunFinishOutcome pattern)

Story's IStoryService.FinishAsync now returns StoryFinishOutcome instead of
FinishResponse directly. Test callsites updated to unwrap .Response.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Services/ArenaTwoPickService.cs

@@ -410,6 +410,8 @@ public class ArenaTwoPickService : IArenaTwoPickService
             BeforeSpotPoint = before,
             AddSpotPoint = aCfg.SpotPointsPerBattle,
             AfterSpotPoint = after,
+            LeveledUp = xp.LeveledUp,
+            ClassId = run.ClassId,
         };
     }
 

SVSim.EmulatedEntrypoint/Services/IStoryService.cs

@@ -10,6 +10,6 @@ public interface IStoryService
     Task<InfoResponse> GetInfoAsync(StoryApiType apiType, int sectionId, int? charaId, long viewerId);
     Task<GetDeckListResponse> GetDeckListAsync(StoryApiType apiType, int storyId, long viewerId);
     Task<StartResponse> StartAsync(StoryApiType apiType, int[] storyIds, long viewerId);
-    Task<FinishResponse> FinishAsync(StoryApiType apiType, FinishRequest req, long viewerId);
+    Task<StoryFinishOutcome> FinishAsync(StoryApiType apiType, FinishRequest req, long viewerId);
     Task<FinishResponse> AllFinishAsync(StoryApiType apiType, int[] storyIds, bool isFinish, long viewerId);
 }

SVSim.EmulatedEntrypoint/Services/StoryService.cs

@@ -486,7 +486,7 @@ public class StoryService : IStoryService
         resp["mission_parameter"] = Array.Empty<object>();
         return resp;
     }
-    public async Task<FinishResponse> FinishAsync(StoryApiType apiType, FinishRequest req, long viewerId)
+    public async Task<StoryFinishOutcome> FinishAsync(StoryApiType apiType, FinishRequest req, long viewerId)
     {
         var chapter = await _master.GetChapterByIdAsync(req.StoryId);
         if (chapter is null)
@@ -497,9 +497,9 @@ public class StoryService : IStoryService
             // StorySubChapter lookup and record progress at the sub's id with isFinish+isSkipped
             // both true (sub-chapters are always narrative-only — no battle settings on the wire).
             var sub = await _master.FindSubChapterByStoryIdAsync(req.StoryId);
-            if (sub is null) return new FinishResponse();
+            if (sub is null) return new StoryFinishOutcome(new FinishResponse(), LeveledUp: false, ClassId: null);
             await _viewer.UpsertProgressAsync(viewerId, req.StoryId, isFinish: true, isSkipped: true);
-            return new FinishResponse();
+            return new StoryFinishOutcome(new FinishResponse(), LeveledUp: false, ClassId: null);
         }
 
         var progress = (await _viewer.GetProgressForChaptersAsync(viewerId, new[] { req.StoryId }))
@@ -581,6 +581,7 @@ public class StoryService : IStoryService
                 resp.StoryRewardList.AddRange(storyRewardDeltas);
             }
 
+            bool leveledUp = false;
             if (firstClear && isPlayShape)
             {
                 // XP grant requires a class_id (only sent on play-shape). No-battle chapters
@@ -593,8 +594,11 @@ public class StoryService : IStoryService
                     resp.GetClassExperience = xp.GetXp.ToString();
                     resp.ClassExperience = xp.TotalXp;
                     resp.ClassLevel = xp.Level.ToString();
+                    leveledUp = xp.LeveledUp;
                 }
             }
+
+            return new StoryFinishOutcome(resp, LeveledUp: leveledUp, ClassId: req.ClassId);
         }
         else
         {
@@ -609,7 +613,7 @@ public class StoryService : IStoryService
             await _viewer.UpsertProgressAsync(viewerId, req.StoryId, isFinish: null, isSkipped: true);
         }
 
-        return resp;
+        return new StoryFinishOutcome(resp, LeveledUp: false, ClassId: null);
     }
     public async Task<FinishResponse> AllFinishAsync(StoryApiType apiType, int[] storyIds, bool isFinish, long viewerId)
     {