feat(store): populate Aurum/cosmetic shops from Vanities

GetStoreItems now also serves the cosmetic stores the client queries
(AurumShop, and the DailyShop_/WeeklyShop_ rotations) from the Vanities
title data: every vanity with StoreData.Amount > 0 is offered for that
price in Aurum (AU). AurumShop lists the full priced catalogue (632
items); the daily/weekly ids show a deterministic rotating slice so they
stay stable within a period but change across periods.

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

src/Prospect.Server.Api/Controllers/ClientController.cs

@@ -210,6 +210,53 @@ public class ClientController : Controller
             _logger.LogWarning(e, "Failed to build store items for store {StoreId}", storeId);
         }
 
+        // Cosmetic / premium stores are backed by the Vanities title data (not Blueprints):
+        // each vanity carries its price in StoreData.Amount, paid in Aurum. AurumShop lists
+        // the whole priced catalogue; the daily/weekly rotations (ids from RequestStore
+        // RotationData) show a deterministic slice so they change over time but stay stable
+        // within a period.
+        var isAurumShop = storeId == "AurumShop";
+        var isDailyShop = storeId.StartsWith("DailyShop_");
+        var isWeeklyShop = storeId.StartsWith("WeeklyShop_");
+        if (store.Count == 0 && (isAurumShop || isDailyShop || isWeeklyShop))
+        {
+            try
+            {
+                var vanityData = _titleDataService.Find(new List<string> { "Vanities" });
+                var vanities = JsonSerializer.Deserialize<List<TitleDataVanityInfo>>(vanityData["Vanities"]);
+                var priced = vanities?
+                    .Where(v => v.StoreData != null && v.StoreData.Amount > 0)
+                    .OrderBy(v => v.Name, StringComparer.Ordinal)
+                    .ToList() ?? new List<TitleDataVanityInfo>();
+
+                IEnumerable<TitleDataVanityInfo> selection = priced;
+                if ((isDailyShop || isWeeklyShop) && priced.Count > 0)
+                {
+                    var size = isWeeklyShop ? 12 : 6;
+                    int.TryParse(storeId[(storeId.IndexOf('_') + 1)..], out var rotation);
+                    var start = (int)(((long)rotation * size) % priced.Count);
+                    selection = Enumerable.Range(0, Math.Min(size, priced.Count))
+                        .Select(i => priced[(start + i) % priced.Count]);
+                }
+
+                uint position = 0;
+                foreach (var vanity in selection)
+                {
+                    store.Add(new FStoreItem
+                    {
+                        ItemId = vanity.Name,
+                        VirtualCurrencyPrices = new Dictionary<string, uint> { ["AU"] = (uint)vanity.StoreData.Amount },
+                        RealCurrencyPrices = new Dictionary<string, uint>(),
+                        DisplayPosition = position++,
+                    });
+                }
+            }
+            catch (Exception e)
+            {
+                _logger.LogWarning(e, "Failed to build vanity store {StoreId}", storeId);
+            }
+        }
+
         _logger.LogInformation("GetStoreItems '{StoreId}': {Count} item(s)", storeId, store.Count);
         return Ok(new ClientResponse<FGetStoreItemsResult>
         {