0.4.0: Claim, Models/ DTOs, compile

LeaderboardSession.ClaimAsync sends onClaim. Generated DTOs live under Models/ with nullable wire fields. Remove incomplete duplicate type files.

skills/rudder-csharp-sdk/reference/stores.md

@@ -0,0 +1,69 @@
+# Stores — `client.Stores` (`StoresService`)
+
+Source: `Services/StoresService.cs`, `Stores/*.cs` (generated DTOs).
+
+In-game stores with offers priced in wallet currencies. Purchasing charges the
+player's wallet and grants the offer contents.
+
+## Methods
+
+```csharp
+// GET /sdk/v1/stores
+public Task<IReadOnlyList<Store>> ListAsync(CancellationToken cancellationToken = default);
+
+// GET /sdk/v1/stores/{slug}
+public Task<Store> GetAsync(string slug, CancellationToken cancellationToken = default);
+
+// POST /sdk/v1/stores/{storeSlug}/offers/{offerId}/purchase
+// When idempotencyKey is null a random GUID is generated; pass a stable key to
+// make retries safe.
+public Task<PurchaseOfferResponse> PurchaseAsync(
+    string storeSlug, string offerId, string? idempotencyKey = null,
+    CancellationToken cancellationToken = default);
+```
+
+## Models (`RudderSdk.Core.Models.Stores`)
+
+```csharp
+public class Store
+{
+    public string? Id { get; set; }                // "id"
+    public string? Slug { get; set; }              // "slug"
+    public string? Name { get; set; }              // "name"
+    public string? Description { get; set; }       // "description"
+    public string? Status { get; set; }            // "status"
+    public string? Environment { get; set; }       // "environment"
+    public string? ProjectId { get; set; }         // "projectId"
+    public string? ScenarioId { get; set; }        // "scenarioId"
+    public JToken? Data { get; set; }              // "data" — free-form
+    public List<Offer>? Offers { get; set; }       // "offers"
+    public DateTimeOffset? CreatedAt { get; set; } // "createdAt"
+    public DateTimeOffset? UpdatedAt { get; set; } // "updatedAt"
+}
+
+public class Offer
+{
+    public string? Id { get; set; }                  // "id"
+    public string? Name { get; set; }                // "name"
+    public OfferPrice? Price { get; set; }           // "price"
+    public List<OfferContent>? Contents { get; set; }// "contents"
+    public int? MaxPurchases { get; set; }           // "maxPurchases"
+    public DateTimeOffset? CreatedAt { get; set; }   // "createdAt"
+    public DateTimeOffset? UpdatedAt { get; set; }   // "updatedAt"
+}
+
+public class OfferPrice   { public long? Amount { get; set; } public string? Currency { get; set; } }
+public class OfferContent { public long? Amount { get; set; } public string? ItemId { get; set; } }
+
+public class PurchaseOfferResponse
+{
+    public string? Error { get; set; }      // "error"
+    public string? PurchaseId { get; set; } // "purchaseId"
+    public bool? Success { get; set; }      // "success"
+}
+```
+
+`PurchaseOfferResponse.Error` carries a business error string when
+`Success` is false — check the flag instead of relying on exceptions alone.
+Purchases also auto-report quest metrics (`purchase.offer:{offerId}`) — see
+quests.md.