feat: rotation shops (daily/weekly) + items insurance + season pass

- RequestStoreRotationData: rotation daily (reset 00:00 UTC) + weekly (lundi) avec
  storeIDs rotatifs déterministes et timers d'expiration corrects.
- EnterMatchmakingStation: traite purchaseInsuranceRequest au déploiement — marque
  les items assurés (Insurance + owner) et débite la prime (TitleData InventoryInsurance).
- FYPurchaseInventoryInsuranceRequest: modèle complété (insuranceId + itemIds).
- RequestClaimFortunaPassRewards: claim saison-correct (S2/S3 séparés, plus d'écrasement)
  + octroi des récompenses depuis catalogue TitleData optionnel (repli sûr sinon).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/Prospect.Server.Api/Services/CloudScript/Functions/RequestStoreRotationData.cs

@@ -35,6 +35,11 @@ public class RequestStoreRotationDataFunction : ICloudScriptFunction<RequestStor
         _httpContextAccessor = httpContextAccessor;
     }
 
+    // Nombre de variantes de rotation (les storeId "DailyShop_N" / "WeeklyShop_N"
+    // permettent au client de distinguer chaque rotation et de rafraîchir son cache).
+    private const int DailyVariants = 8;
+    private const int WeeklyVariants = 4;
+
     public async Task<RequestStoreRotationDataResponse> ExecuteAsync(RequestStoreRotationDataRequest request)
     {
         var context = _httpContextAccessor.HttpContext;
@@ -43,18 +48,33 @@ public class RequestStoreRotationDataFunction : ICloudScriptFunction<RequestStor
             throw new CloudScriptException("CloudScript was not called within a http request");
         }
 
-        // TODO: Get and save store rotation data
+        var now = DateTime.UtcNow;
+
+        // Rotation quotidienne : expire au prochain minuit UTC ; l'index de rotation
+        // est le nombre de jours écoulés depuis l'epoch (déterministe, stable).
+        var todayUtc = now.Date;
+        var dailyExpiration = todayUtc.AddDays(1);
+        var dayIndex = (int)(todayUtc - DateTime.UnixEpoch.Date).TotalDays;
+        var dailyStoreId = $"DailyShop_{dayIndex % DailyVariants}";
+
+        // Rotation hebdomadaire : expire au prochain lundi 00:00 UTC.
+        // DayOfWeek : dimanche=0 ; on ramène lundi=0.
+        var daysSinceMonday = ((int)todayUtc.DayOfWeek + 6) % 7;
+        var weekStart = todayUtc.AddDays(-daysSinceMonday);
+        var weeklyExpiration = weekStart.AddDays(7);
+        var weekIndex = (int)Math.Floor((weekStart - DateTime.UnixEpoch.Date).TotalDays / 7);
+        var weeklyStoreId = $"WeeklyShop_{weekIndex % WeeklyVariants}";
 
         return new RequestStoreRotationDataResponse
         {
             Error = "",
             DailyStoreData = new StoreRotationData {
-                StoreID = "DailyShop",
-                ExpirationData = DateTime.UtcNow.AddDays(1)
+                StoreID = dailyStoreId,
+                ExpirationData = dailyExpiration
             },
             WeeklyStoreData = new StoreRotationData {
-                StoreID = "WeeklyShop",
-                ExpirationData = DateTime.UtcNow.AddDays(1)
+                StoreID = weeklyStoreId,
+                ExpirationData = weeklyExpiration
             }
         };
     }