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/Controllers/ArenaColosseumBattleController.cs

@@ -4,6 +4,7 @@ using Microsoft.AspNetCore.Mvc;
 using SVSim.BattleNode.Bridge;
 using SVSim.Database;
 using SVSim.Database.Repositories.Viewer;
+using SVSim.Database.Services;
 using SVSim.Database.Services.BattleXp;
 using SVSim.EmulatedEntrypoint.Constants;
 using SVSim.EmulatedEntrypoint.Matching;
@@ -40,6 +41,7 @@ public sealed class ArenaColosseumBattleController : ControllerBase
     private readonly IColosseumProgressionService _progression;
     private readonly IViewerRepository _viewers;
     private readonly IBattleXpService _xp;
+    private readonly IMissionProgressService _missionProgress;
     private readonly SVSimDbContext _db;
     private readonly ILogger<ArenaColosseumBattleController> _log;
 
@@ -50,6 +52,7 @@ public sealed class ArenaColosseumBattleController : ControllerBase
         IColosseumProgressionService progression,
         IViewerRepository viewers,
         IBattleXpService xp,
+        IMissionProgressService missionProgress,
         SVSimDbContext db,
         ILogger<ArenaColosseumBattleController> log)
     {
@@ -59,6 +62,7 @@ public sealed class ArenaColosseumBattleController : ControllerBase
         _progression = progression;
         _viewers = viewers;
         _xp = xp;
+        _missionProgress = missionProgress;
         _db = db;
         _log = log;
     }
@@ -174,6 +178,7 @@ public sealed class ArenaColosseumBattleController : ControllerBase
         }
 
         int gainXp = 0, totalXp = 0, level = 1;
+        bool leveledUp = false;
         var viewer = await _viewers.LoadForBattleXpGrantAsync(vid, ct);
         if (viewer is not null)
         {
@@ -182,6 +187,13 @@ public sealed class ArenaColosseumBattleController : ControllerBase
             gainXp = xp.GetXp;
             totalXp = xp.TotalXp;
             level = xp.Level == 0 ? 1 : xp.Level;
+            leveledUp = xp.LeveledUp;
+        }
+
+        if (leveledUp)
+        {
+            await _missionProgress.RecordEventAsync(
+                vid, MissionEventKeys.ClassLevel.UpAll(req.ClassId), ct: ct);
         }
 
         // result_code 3502 ("battle already finished") is the idempotent-retry tolerance per