feat(inventory): read-side methods on IInventoryService + tx

EffectiveBalance/OwnsCard/OwnsCosmetic on the tx are freeplay-aware
against the live viewer. EffectiveOwnedCardsAsync/EffectiveCosmeticsAsync
on the service mirror today's ViewerEntitlements projections (used by
/load/index).

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

SVSim.Database/Services/Inventory/InventoryService.cs

@@ -60,13 +60,71 @@ public sealed class InventoryService : IInventoryService
         return new InventoryTransaction(_db, dbTx, viewer, freeplay, _log);
     }
 
-    // Stubs for later tasks.
-    public Task<IReadOnlyList<OwnedCardEntry>> EffectiveOwnedCardsAsync(Viewer viewer, CancellationToken ct = default)
-        => throw new NotImplementedException();
-
-    public Task<EffectiveCosmetics> EffectiveCosmeticsAsync(Viewer viewer, CancellationToken ct = default)
-        => throw new NotImplementedException();
-
     public long EffectiveBalance(Viewer viewer, SpendCurrency currency)
-        => throw new NotImplementedException();
+    {
+        var cfg = _config.Get<FreeplayConfig>();
+        if (cfg.Enabled && currency != SpendCurrency.SpotPoint)
+            return checked((long)cfg.CurrencyAmount);
+
+        return currency switch
+        {
+            SpendCurrency.Crystal => (long)viewer.Currency.Crystals,
+            SpendCurrency.Rupee => (long)viewer.Currency.Rupees,
+            SpendCurrency.RedEther => (long)viewer.Currency.RedEther,
+            SpendCurrency.SpotPoint => (long)viewer.Currency.SpotPoints,
+            _ => throw new ArgumentOutOfRangeException(nameof(currency)),
+        };
+    }
+
+    public async Task<IReadOnlyList<OwnedCardEntry>> EffectiveOwnedCardsAsync(
+        Viewer viewer, CancellationToken ct = default)
+    {
+        var defaults = await _cards.GetDefaultCards();
+        var defaultIds = defaults.Select(c => c.Id).ToHashSet();
+        var cfg = _config.Get<FreeplayConfig>();
+
+        if (cfg.Enabled)
+        {
+            var all = await _cards.GetAll(onlyCollectible: true);
+            return all
+                .Select(c => new OwnedCardEntry
+                {
+                    Card = c,
+                    Count = cfg.CardCopies,
+                    IsProtected = defaultIds.Contains(c.Id),
+                })
+                .ToList();
+        }
+
+        var owned = viewer.Cards.Where(c => c.Count > 0 && !defaultIds.Contains(c.Card.Id));
+        return owned
+            .Concat(defaults.Select(bc => new OwnedCardEntry { Card = bc, Count = 3, IsProtected = true }))
+            .ToList();
+    }
+
+    public async Task<EffectiveCosmetics> EffectiveCosmeticsAsync(
+        Viewer viewer, CancellationToken ct = default)
+    {
+        var allSkins = await _collection.GetLeaderSkins();
+        var cfg = _config.Get<FreeplayConfig>();
+
+        if (cfg.Enabled)
+        {
+            return new EffectiveCosmetics(
+                await _collection.GetAllSleeveIds(),
+                await _collection.GetAllEmblemIds(),
+                await _collection.GetAllDegreeIds(),
+                await _collection.GetAllMyPageBackgroundIds(),
+                allSkins,
+                allSkins.Select(s => s.Id).ToHashSet());
+        }
+
+        return new EffectiveCosmetics(
+            viewer.Sleeves.Select(s => s.Id).ToList(),
+            viewer.Emblems.Select(e => e.Id).ToList(),
+            viewer.Degrees.Select(d => d.Id).ToList(),
+            viewer.MyPageBackgrounds.Select(m => m.Id).ToList(),
+            allSkins,
+            viewer.LeaderSkins.Select(s => s.Id).ToHashSet());
+    }
 }

SVSim.Database/Services/Inventory/InventoryTransaction.cs

@@ -237,9 +237,37 @@ internal sealed class InventoryTransaction : IInventoryTransaction
         _ => false,
     };
 
-    public long EffectiveBalance(SpendCurrency currency) => throw new NotImplementedException();
-    public bool OwnsCard(long cardId) => throw new NotImplementedException();
-    public bool OwnsCosmetic(CosmeticType type, int id) => throw new NotImplementedException();
+    public long EffectiveBalance(SpendCurrency currency)
+    {
+        if (_freeplay.Enabled && currency != SpendCurrency.SpotPoint)
+            return checked((long)_freeplay.CurrencyAmount);
+
+        return currency switch
+        {
+            SpendCurrency.Crystal => (long)Viewer.Currency.Crystals,
+            SpendCurrency.Rupee => (long)Viewer.Currency.Rupees,
+            SpendCurrency.RedEther => (long)Viewer.Currency.RedEther,
+            SpendCurrency.SpotPoint => (long)Viewer.Currency.SpotPoints,
+            _ => throw new ArgumentOutOfRangeException(nameof(currency)),
+        };
+    }
+
+    public bool OwnsCard(long cardId)
+        => _freeplay.Enabled || Viewer.Cards.Any(c => c.Card.Id == cardId && c.Count > 0);
+
+    public bool OwnsCosmetic(CosmeticType type, int id)
+    {
+        if (_freeplay.Enabled) return true;
+        return type switch
+        {
+            CosmeticType.Sleeve => Viewer.Sleeves.Any(s => s.Id == id),
+            CosmeticType.Emblem => Viewer.Emblems.Any(e => e.Id == id),
+            CosmeticType.Degree => Viewer.Degrees.Any(d => d.Id == id),
+            CosmeticType.Skin => Viewer.LeaderSkins.Any(s => s.Id == id),
+            CosmeticType.MyPageBG => Viewer.MyPageBackgrounds.Any(m => m.Id == id),
+            _ => false,
+        };
+    }
 
     public async Task<InventoryCommitResult> CommitAsync(CancellationToken ct = default)
     {