feat(replay): add ReplayHistoryReader for newest-first list query

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

SVSim.Database/Services/Replay/IReplayHistoryReader.cs

@@ -0,0 +1,7 @@
+namespace SVSim.Database.Services.Replay;
+
+public interface IReplayHistoryReader
+{
+    /// <summary>Newest-first by CreateTime. Caps at <paramref name="take"/> (default 50).</summary>
+    Task<IReadOnlyList<ReplayHistoryEntry>> GetRecentAsync(long viewerId, int take, CancellationToken ct);
+}

SVSim.Database/Services/Replay/ReplayHistoryEntry.cs

@@ -0,0 +1,27 @@
+namespace SVSim.Database.Services.Replay;
+
+/// <summary>
+/// Read-side row returned by <see cref="IReplayHistoryReader"/>. The /replay/info
+/// controller maps this to its wire DTO (all-stringified per prod capture).
+/// </summary>
+public sealed record ReplayHistoryEntry(
+    long   BattleId,
+    int    BattleType,
+    int    DeckFormat,
+    int    TwoPickType,
+    int    IsLimitTurn,
+    int    SelfClassId,
+    int    SelfSubClassId,
+    int    SelfCharaId,
+    string SelfRotationId,
+    int    OpponentClassId,
+    int    OpponentSubClassId,
+    int    OpponentCharaId,
+    string OpponentName,
+    string OpponentCountryCode,
+    long   OpponentEmblemId,
+    long   OpponentDegreeId,
+    string OpponentRotationId,
+    bool   IsWin,
+    DateTime BattleStartTime,
+    DateTime CreateTime);

SVSim.Database/Services/Replay/ReplayHistoryReader.cs

@@ -0,0 +1,27 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace SVSim.Database.Services.Replay;
+
+public sealed class ReplayHistoryReader : IReplayHistoryReader
+{
+    private readonly SVSimDbContext _db;
+
+    public ReplayHistoryReader(SVSimDbContext db) => _db = db;
+
+    public async Task<IReadOnlyList<ReplayHistoryEntry>> GetRecentAsync(long viewerId, int take, CancellationToken ct)
+    {
+        return await _db.ViewerBattleHistories
+            .AsNoTracking()
+            .Where(h => h.ViewerId == viewerId)
+            .OrderByDescending(h => h.CreateTime)
+            .Take(take)
+            .Select(h => new ReplayHistoryEntry(
+                h.BattleId, h.BattleType, h.DeckFormat, h.TwoPickType, h.IsLimitTurn,
+                h.SelfClassId, h.SelfSubClassId, h.SelfCharaId, h.SelfRotationId,
+                h.OpponentClassId, h.OpponentSubClassId, h.OpponentCharaId,
+                h.OpponentName, h.OpponentCountryCode,
+                h.OpponentEmblemId, h.OpponentDegreeId, h.OpponentRotationId,
+                h.IsWin, h.BattleStartTime, h.CreateTime))
+            .ToListAsync(ct);
+    }
+}

SVSim.EmulatedEntrypoint/Program.cs

@@ -119,6 +119,7 @@ public class Program
 
         builder.Services.AddSingleton<IBattleContextStore, InMemoryBattleContextStore>();
         builder.Services.AddScoped<IBattleHistoryWriter, BattleHistoryWriter>();
+        builder.Services.AddScoped<IReplayHistoryReader, ReplayHistoryReader>();
 
         // Deck-code mint/resolve uses IMemoryCache for ephemeral (3-min TTL) storage; no DB
         // row, no migration. Singleton because the cache + RNG seam are process-wide.