feat(replay): wire finish hook for rank-battle family

Finish now consumes the stashed BattleContext, records a
ViewerBattleHistory row (idempotent + retention-capped), and
calls IPlayedTogetherWriter for human PvP (skipped for AI).

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

SVSim.UnitTests/Controllers/ReplayControllerTests.cs

@@ -4,6 +4,7 @@ using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using SVSim.Database;
 using SVSim.Database.Models;
+using SVSim.Database.Services.Replay;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Replay;
 using SVSim.UnitTests.Infrastructure;
 
@@ -102,6 +103,76 @@ public class ReplayControllerTests
         Assert.That(resp.StatusCode, Is.EqualTo(HttpStatusCode.BadRequest));
     }
 
+    [Test]
+    public async Task AiRankFinish_writes_history_row_visible_from_ReplayInfo()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(steamId: 76_561_198_000_000_001UL);
+
+        // Inject a pre-stashed BattleContext as if /ai_rotation_rank_battle/start had run.
+        var store = factory.Services.GetRequiredService<IBattleContextStore>();
+        store.Set(viewerId, new BattleContext(
+            BattleId: 234_471_983_876L,
+            BattleType: 2, DeckFormat: 0, TwoPickType: 0,
+            SelfClassId: 8, SelfSubClassId: 0, SelfCharaId: 8, SelfRotationId: "0",
+            OpponentViewerId: 0, OpponentName: "BotName", OpponentClassId: 5,
+            OpponentSubClassId: 0, OpponentCharaId: 805, OpponentCountryCode: "",
+            OpponentEmblemId: 721_341_010L, OpponentDegreeId: 120_023L,
+            OpponentRotationId: "0",
+            BattleStartTime: new DateTime(2026, 6, 4, 17, 13, 13, DateTimeKind.Utc)));
+
+        var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var finishResp = await client.PostAsJsonAsync("/ai_rotation_rank_battle/finish", new
+        {
+            viewer_id = "0",
+            steam_id = 0,
+            steam_session_ticket = "",
+            battle_result = 1, // win
+            class_id = 8,
+            total_turn = 7,
+            evolve_count = 1,
+            enemy_evolve_count = 0,
+            sdtrb = 0,
+        });
+        Assert.That(finishResp.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+
+        var infoBody = await client.PostAsJsonAsync("/replay/info", EmptyBody())
+            .ContinueWith(t => t.Result.Content.ReadFromJsonAsync<ReplayInfoResponseDto>())
+            .Unwrap();
+
+        Assert.That(infoBody!.ReplayList, Has.Count.EqualTo(1));
+        var row = infoBody.ReplayList[0];
+        Assert.That(row.BattleId, Is.EqualTo("234471983876"));
+        Assert.That(row.OpponentName, Is.EqualTo("BotName"));
+        Assert.That(row.IsWin, Is.EqualTo("1"));
+        Assert.That(row.OpponentEmblemId, Is.EqualTo("721341010"));
+    }
+
+    [Test]
+    public async Task AiRankFinish_with_no_stashed_context_does_not_crash()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(steamId: 76_561_198_000_000_001UL);
+
+        var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var finishResp = await client.PostAsJsonAsync("/ai_rotation_rank_battle/finish", new
+        {
+            viewer_id = "0",
+            steam_id = 0,
+            steam_session_ticket = "",
+            battle_result = 0,
+            class_id = 1, total_turn = 1, evolve_count = 0, enemy_evolve_count = 0, sdtrb = 0,
+        });
+        Assert.That(finishResp.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+
+        var infoBody = await client.PostAsJsonAsync("/replay/info", EmptyBody())
+            .ContinueWith(t => t.Result.Content.ReadFromJsonAsync<ReplayInfoResponseDto>())
+            .Unwrap();
+        Assert.That(infoBody!.ReplayList, Is.Empty);
+    }
+
     private static ViewerBattleHistory NewRow(long viewerId, long battleId, DateTime createTime) => new()
     {
         ViewerId = viewerId,