feat(battle-xp): wire rank + AI-rank /finish through IBattleXpService

- RankBattleController.Finish (covers all 4 URLs: rotation, unlimited,
  ai_rotation, ai_unlimited) now grants win/loss XP via IBattleXpService
  with BattleXpMode.Rank. Uses req.ClassId from wire.
- Tests updated: AI-variant win asserts new XP values; consistency-loss
  asserts loss XP. Added persistence test on /unlimited_rank_battle/finish.

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

SVSim.EmulatedEntrypoint/Controllers/RankBattleController.cs

@@ -2,7 +2,10 @@ using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using SVSim.BattleNode.Bridge;
 using SVSim.BattleNode.Sessions;
+using SVSim.Database;
 using SVSim.Database.Enums;
+using SVSim.Database.Repositories.Viewer;
+using SVSim.Database.Services.BattleXp;
 using SVSim.Database.Services.Friend;
 using SVSim.Database.Services.Replay;
 using SVSim.EmulatedEntrypoint.Constants;
@@ -33,6 +36,9 @@ public sealed class RankBattleController : ControllerBase
     private readonly IBattleContextStore _battleContextStore;
     private readonly IBattleHistoryWriter _historyWriter;
     private readonly IPlayedTogetherWriter _playedTogetherWriter;
+    private readonly IViewerRepository _viewers;
+    private readonly IBattleXpService _xp;
+    private readonly SVSimDbContext _db;
     private readonly ILogger<RankBattleController> _log;
 
     public RankBattleController(
@@ -43,6 +49,9 @@ public sealed class RankBattleController : ControllerBase
         IBattleContextStore battleContextStore,
         IBattleHistoryWriter historyWriter,
         IPlayedTogetherWriter playedTogetherWriter,
+        IViewerRepository viewers,
+        IBattleXpService xp,
+        SVSimDbContext db,
         ILogger<RankBattleController> log)
     {
         _resolver = resolver;
@@ -52,6 +61,9 @@ public sealed class RankBattleController : ControllerBase
         _battleContextStore = battleContextStore;
         _historyWriter = historyWriter;
         _playedTogetherWriter = playedTogetherWriter;
+        _viewers = viewers;
+        _xp = xp;
+        _db = db;
         _log = log;
     }
 
@@ -114,10 +126,23 @@ public sealed class RankBattleController : ControllerBase
                 ct);
         }
 
+        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, isWin, BattleXpMode.Rank, ct);
+            await _db.SaveChangesAsync(ct);
+            gainXp = xp.GetXp;
+            totalXp = xp.TotalXp;
+            level = xp.Level == 0 ? 1 : xp.Level;
+        }
+
         return Ok(new RankBattleFinishResponseDto
         {
             BattleResult = req.BattleResult,
-            // All other fields default to 0 in the DTO (ClassLevel defaults to 1).
+            GetClassExperience = gainXp,
+            ClassExperience = totalXp,
+            ClassLevel = level,
         });
     }
 

SVSim.UnitTests/Controllers/RankBattleControllerTests.cs

@@ -1,9 +1,11 @@
 using System.Net.Http.Json;
 using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using NUnit.Framework;
 using SVSim.BattleNode.Bridge;
 using SVSim.BattleNode.Sessions;
+using SVSim.Database;
 using SVSim.Database.Enums;
 using SVSim.EmulatedEntrypoint.Services;
 using SVSim.UnitTests.Infrastructure;
@@ -231,13 +233,14 @@ public class RankBattleControllerTests
     }
 
     [Test]
-    public async Task Finish_emits_stubbed_zeros_with_battle_result_echo()
+    public async Task Finish_grants_win_xp_via_ai_variant()
     {
         await using var factory = new SVSimTestFactory();
         var viewerId = await factory.SeedViewerAsync();
         var client = factory.CreateAuthenticatedClient(viewerId);
 
-        var resp = await client.PostAsJsonAsync("/ai_rotation_rank_battle/finish", FinishBody(battleResult: 1));
+        var resp = await client.PostAsJsonAsync(
+            "/ai_rotation_rank_battle/finish", FinishBody(battleResult: 1, classId: 1));
 
         Assert.That(resp.IsSuccessStatusCode, Is.True);
         using var doc = JsonDocument.Parse(await resp.Content.ReadAsStringAsync());
@@ -245,7 +248,10 @@ public class RankBattleControllerTests
         Assert.That(data.GetProperty("battle_result").GetInt32(), Is.EqualTo(1));
         Assert.That(data.GetProperty("rank").GetInt32(), Is.EqualTo(0));
         Assert.That(data.GetProperty("after_battle_point").GetInt32(), Is.EqualTo(0));
-        Assert.That(data.GetProperty("class_level").GetInt32(), Is.EqualTo(1));
+        // BattleXpConfig.XpPerWin=100, classexp.csv L1=50 → land at L2 with 50 carry.
+        Assert.That(data.GetProperty("get_class_experience").GetInt32(), Is.EqualTo(100));
+        Assert.That(data.GetProperty("class_experience").GetInt32(), Is.EqualTo(50));
+        Assert.That(data.GetProperty("class_level").GetInt32(), Is.EqualTo(2));
     }
 
     [Test]
@@ -255,9 +261,32 @@ public class RankBattleControllerTests
         var viewerId = await factory.SeedViewerAsync();
         var client = factory.CreateAuthenticatedClient(viewerId);
 
-        var resp = await client.PostAsJsonAsync("/rotation_rank_battle/finish", FinishBody(battleResult: 2));
+        var resp = await client.PostAsJsonAsync("/rotation_rank_battle/finish", FinishBody(battleResult: 2, classId: 1));
 
         using var doc = JsonDocument.Parse(await resp.Content.ReadAsStringAsync());
         Assert.That(doc.RootElement.GetProperty("battle_result").GetInt32(), Is.EqualTo(2));
+        // battle_result==2 is loss-shaped: XpPerLoss=25 (< L1 threshold=50).
+        Assert.That(doc.RootElement.GetProperty("get_class_experience").GetInt32(), Is.EqualTo(25));
+        Assert.That(doc.RootElement.GetProperty("class_experience").GetInt32(), Is.EqualTo(25));
+        Assert.That(doc.RootElement.GetProperty("class_level").GetInt32(), Is.EqualTo(1));
+    }
+
+    [Test]
+    public async Task Finish_persists_class_xp_to_viewer()
+    {
+        await using var factory = new SVSimTestFactory();
+        var viewerId = await factory.SeedViewerAsync();
+        var client = factory.CreateAuthenticatedClient(viewerId);
+
+        await client.PostAsJsonAsync(
+            "/unlimited_rank_battle/finish", FinishBody(battleResult: 1, classId: 3));
+
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var v = await db.Viewers.Include(x => x.Classes).ThenInclude(c => c.Class)
+            .FirstAsync(x => x.Id == viewerId);
+        var cls3 = v.Classes.Single(c => c.Class.Id == 3);
+        Assert.That(cls3.Level, Is.EqualTo(2));
+        Assert.That(cls3.Exp, Is.EqualTo(50));
     }
 }