feat(missions): ViewerMissionStateService — lazy materialize achievements + assign slots

Reads existing state from DB on each call (don't trust navigation
property — caller may pass it stale or double-tracked). Adds via DbSet
only, not via navigation property, to avoid EF double-tracking.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

SVSim.UnitTests/Services/ViewerMissionStateServiceTests.cs

@@ -0,0 +1,129 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SVSim.Bootstrap.Importers;
+using SVSim.Database;
+using SVSim.Database.Models;
+using SVSim.EmulatedEntrypoint.Services;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Services;
+
+public class ViewerMissionStateServiceTests
+{
+    private static string SeedDir => Path.Combine(AppContext.BaseDirectory, "Data", "seeds");
+
+    private static async Task ImportCatalogsAsync(IServiceProvider sp)
+    {
+        using var scope = sp.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        await new MissionCatalogImporter().ImportAsync(db, SeedDir);
+        await new AchievementCatalogImporter().ImportAsync(db, SeedDir);
+    }
+
+    private static async Task<long> SeedViewer(IServiceProvider sp)
+    {
+        using var scope = sp.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var v = new Viewer { DisplayName = "test", ShortUdid = 1, LastLogin = DateTime.UtcNow };
+        db.Viewers.Add(v);
+        await db.SaveChangesAsync();
+        return v.Id;
+    }
+
+    [Test]
+    public async Task EnsureCurrent_creates_one_achievement_per_catalog_type()
+    {
+        using var factory = new SVSimTestFactory();
+        await ImportCatalogsAsync(factory.Services);
+        long vid = await SeedViewer(factory.Services);
+
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var viewer = await db.Viewers
+            .Include(x => x.Achievements).Include(x => x.Missions)
+            .FirstAsync(x => x.Id == vid);
+
+        var svc = scope.ServiceProvider.GetRequiredService<IViewerMissionStateService>();
+        await svc.EnsureCurrentAsync(viewer);
+        await db.SaveChangesAsync();
+
+        int catalogTypeCount = await db.AchievementCatalog
+            .Select(e => e.AchievementType).Distinct().CountAsync();
+        int viewerCount = await db.ViewerAchievements.CountAsync(a => a.ViewerId == vid);
+        Assert.That(viewerCount, Is.EqualTo(catalogTypeCount));
+    }
+
+    [Test]
+    public async Task EnsureCurrent_is_idempotent()
+    {
+        using var factory = new SVSimTestFactory();
+        await ImportCatalogsAsync(factory.Services);
+        long vid = await SeedViewer(factory.Services);
+
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var viewer = await db.Viewers
+            .Include(x => x.Achievements).Include(x => x.Missions)
+            .FirstAsync(x => x.Id == vid);
+
+        var svc = scope.ServiceProvider.GetRequiredService<IViewerMissionStateService>();
+        await svc.EnsureCurrentAsync(viewer);
+        await db.SaveChangesAsync();
+        int after1 = await db.ViewerAchievements.CountAsync(a => a.ViewerId == vid);
+        await svc.EnsureCurrentAsync(viewer);
+        await db.SaveChangesAsync();
+        int after2 = await db.ViewerAchievements.CountAsync(a => a.ViewerId == vid);
+        Assert.That(after2, Is.EqualTo(after1));
+    }
+
+    [Test]
+    public async Task EnsureCurrent_assigns_daily_and_weekly_slots_from_pool()
+    {
+        using var factory = new SVSimTestFactory();
+        await ImportCatalogsAsync(factory.Services);
+        long vid = await SeedViewer(factory.Services);
+
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var viewer = await db.Viewers
+            .Include(x => x.Missions).Include(x => x.Achievements)
+            .FirstAsync(x => x.Id == vid);
+
+        var svc = scope.ServiceProvider.GetRequiredService<IViewerMissionStateService>();
+        await svc.EnsureCurrentAsync(viewer);
+        await db.SaveChangesAsync();
+
+        var slots = await db.ViewerMissions
+            .Where(m => m.ViewerId == vid).OrderBy(m => m.Slot).ToListAsync();
+        Assert.That(slots.Count, Is.EqualTo(4), "1 daily + 3 weekly");
+        Assert.That(slots.Select(s => s.Slot), Is.EquivalentTo(new[] { 0, 1, 2, 3 }));
+
+        var dailyCatalogId = slots[0].MissionCatalogId;
+        var dailyCatalog = await db.MissionCatalog.FindAsync(dailyCatalogId);
+        Assert.That(dailyCatalog!.LotType, Is.EqualTo(6), "slot 0 = daily, lot_type 6");
+    }
+
+    [Test]
+    public async Task EnsureCurrent_picks_distinct_weekly_missions()
+    {
+        using var factory = new SVSimTestFactory();
+        await ImportCatalogsAsync(factory.Services);
+        long vid = await SeedViewer(factory.Services);
+
+        using var scope = factory.Services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var viewer = await db.Viewers
+            .Include(x => x.Missions).Include(x => x.Achievements)
+            .FirstAsync(x => x.Id == vid);
+
+        var svc = scope.ServiceProvider.GetRequiredService<IViewerMissionStateService>();
+        await svc.EnsureCurrentAsync(viewer);
+        await db.SaveChangesAsync();
+
+        var weeklyIds = await db.ViewerMissions
+            .Where(m => m.ViewerId == vid && m.Slot != 0)
+            .Select(m => m.MissionCatalogId).ToListAsync();
+        Assert.That(weeklyIds.Distinct().Count(), Is.EqualTo(weeklyIds.Count),
+            "weekly slots must have distinct catalog ids");
+    }
+}