feat(battle-xp): wire colosseum /finish through IBattleXpService, extend response DTO

- ColosseumBattleFinishResponseDto gains get_class_experience,
  class_experience, class_level. Client-safe: same BattleFinishResponsProcessing
  handles all three keys as ints (decomp verified).
- ArenaColosseumBattleController.FinishInternal grants win/loss XP via
  IBattleXpService with BattleXpMode.Colosseum for both /colosseum_battle/finish
  and /colosseum_rank_battle/finish URLs.
- Existing win test extended: XP wire assertions + persistence check.

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

SVSim.EmulatedEntrypoint/Controllers/ArenaColosseumBattleController.cs

@@ -2,7 +2,9 @@ using System.Text.Json;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using SVSim.BattleNode.Bridge;
+using SVSim.Database;
 using SVSim.Database.Repositories.Viewer;
+using SVSim.Database.Services.BattleXp;
 using SVSim.EmulatedEntrypoint.Constants;
 using SVSim.EmulatedEntrypoint.Matching;
 using SVSim.EmulatedEntrypoint.Models.Dtos.ArenaColosseum;
@@ -36,6 +38,9 @@ public sealed class ArenaColosseumBattleController : ControllerBase
     private readonly IMatchingResolver _resolver;
     private readonly IArenaColosseumRunRepository _runs;
     private readonly IColosseumProgressionService _progression;
+    private readonly IViewerRepository _viewers;
+    private readonly IBattleXpService _xp;
+    private readonly SVSimDbContext _db;
     private readonly ILogger<ArenaColosseumBattleController> _log;
 
     public ArenaColosseumBattleController(
@@ -43,12 +48,18 @@ public sealed class ArenaColosseumBattleController : ControllerBase
         IMatchingResolver resolver,
         IArenaColosseumRunRepository runs,
         IColosseumProgressionService progression,
+        IViewerRepository viewers,
+        IBattleXpService xp,
+        SVSimDbContext db,
         ILogger<ArenaColosseumBattleController> log)
     {
         _ctxBuilder = ctxBuilder;
         _resolver = resolver;
         _runs = runs;
         _progression = progression;
+        _viewers = viewers;
+        _xp = xp;
+        _db = db;
         _log = log;
     }
 
@@ -162,10 +173,27 @@ public sealed class ArenaColosseumBattleController : ControllerBase
             await _runs.UpsertAsync(run);
         }
 
+        int gainXp = 0, totalXp = 0, level = 1;
+        var viewer = await _viewers.LoadForBattleXpGrantAsync(vid, ct);
+        if (viewer is not null)
+        {
+            var xp = await _xp.GrantAsync(viewer, req.ClassId, req.BattleResult == 1, BattleXpMode.Colosseum, ct);
+            await _db.SaveChangesAsync(ct);
+            gainXp = xp.GetXp;
+            totalXp = xp.TotalXp;
+            level = xp.Level == 0 ? 1 : xp.Level;
+        }
+
         // result_code 3502 ("battle already finished") is the idempotent-retry tolerance per
         // FinishTaskBase.IsEffectiveErrorCode. Server emits standard data; the translation
         // middleware sets the wire result_code via data_headers from the response envelope.
-        return Ok(new ColosseumBattleFinishResponseDto { BattleResult = req.BattleResult });
+        return Ok(new ColosseumBattleFinishResponseDto
+        {
+            BattleResult = req.BattleResult,
+            GetClassExperience = gainXp,
+            ClassExperience = totalXp,
+            ClassLevel = level,
+        });
     }
 
     private static List<int> ParseIntList(string json) =>

SVSim.EmulatedEntrypoint/Models/Dtos/ArenaColosseum/BattleFinishRequestDto.cs

@@ -46,4 +46,13 @@ public sealed class ColosseumBattleFinishResponseDto
 {
     [JsonPropertyName("battle_result")] [Key("battle_result")]
     public int BattleResult { get; set; }
+
+    [JsonPropertyName("get_class_experience")] [Key("get_class_experience")]
+    public int GetClassExperience { get; set; }
+
+    [JsonPropertyName("class_experience")] [Key("class_experience")]
+    public int ClassExperience { get; set; }
+
+    [JsonPropertyName("class_level")] [Key("class_level")]
+    public int ClassLevel { get; set; } = 1;
 }

SVSim.UnitTests/Controllers/ArenaColosseumBattleControllerTests.cs

@@ -118,6 +118,12 @@ public class ArenaColosseumBattleControllerTests
         var resp = await client.PostAsync("/colosseum_battle/finish", JsonContent.Create(req));
         Assert.That(resp.StatusCode, Is.EqualTo(HttpStatusCode.OK));
 
+        // XP wire assertions
+        using var doc = JsonDocument.Parse(await resp.Content.ReadAsStringAsync());
+        Assert.That(doc.RootElement.GetProperty("get_class_experience").GetInt32(), Is.EqualTo(100));
+        Assert.That(doc.RootElement.GetProperty("class_experience").GetInt32(), Is.EqualTo(50));
+        Assert.That(doc.RootElement.GetProperty("class_level").GetInt32(), Is.EqualTo(2));
+
         using var scope = factory.Services.CreateScope();
         var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
         var run = await db.ViewerArenaColosseumRuns.FirstAsync(r => r.ViewerId == vid);
@@ -125,6 +131,13 @@ public class ArenaColosseumBattleControllerTests
         Assert.That(run.LossCount, Is.EqualTo(0));
         Assert.That(run.BattleCountThisRound, Is.EqualTo(1));
         Assert.That(run.ResultListJson, Is.EqualTo("[1]"));
+
+        // Persisted class XP on viewer
+        var v = await db.Viewers.Include(x => x.Classes).ThenInclude(c => c.Class)
+            .FirstAsync(x => x.Id == vid);
+        var cls1 = v.Classes.Single(c => c.Class.Id == 1);
+        Assert.That(cls1.Level, Is.EqualTo(2));
+        Assert.That(cls1.Exp, Is.EqualTo(50));
     }
 
     [Test]