feat(packs): PackDrawTable aggregate + IPackDrawTableRepository

Aggregate (Config + SlotRates + CardWeights) and a single-pack getter
loaded as one unit per /pack/open. PackOpenService consumes the
aggregate; tests use the production seed (fixture overlay) to validate
shape.

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

SVSim.UnitTests/Repositories/PackDrawTableRepositoryTests.cs

@@ -0,0 +1,43 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SVSim.Bootstrap.Importers;
+using SVSim.Database;
+using SVSim.Database.Repositories.PackDrawTables;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Repositories;
+
+public class PackDrawTableRepositoryTests
+{
+    private static string SeedDir => Path.Combine(AppContext.BaseDirectory, "Data", "seeds");
+
+    [Test]
+    public async Task GetAsync_returns_null_when_pack_unseeded()
+    {
+        using var factory = new SVSimTestFactory();
+        using var scope = factory.Services.CreateScope();
+        var repo = scope.ServiceProvider.GetRequiredService<IPackDrawTableRepository>();
+
+        var table = await repo.GetAsync(123456);
+
+        Assert.That(table, Is.Null);
+    }
+
+    [Test]
+    public async Task GetAsync_returns_config_slot_rates_and_card_weights_for_seeded_pack()
+    {
+        using var factory = new SVSimTestFactory();
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var repo = scope.ServiceProvider.GetRequiredService<IPackDrawTableRepository>();
+
+        await new PackDrawTableImporter().ImportAsync(db, SeedDir);
+        var table = await repo.GetAsync(10000);
+
+        Assert.That(table, Is.Not.Null);
+        Assert.That(table!.Config.AnimationRatePct, Is.EqualTo(8.0));
+        Assert.That(table.SlotRates.Count, Is.EqualTo(7));
+        Assert.That(table.CardWeights.Count, Is.EqualTo(3));
+        Assert.That(table.CardWeights.All(w => w.PackId == 10000), Is.True);
+    }
+}