feat(sleeve): shop catalog + /sleeve/{info,buy} endpoints

Schema: SleeveShopSeries -> SleeveShopProducts -> Rewards (owned).
Migration AddSleeveShop creates 3 tables with FK cascade.

Importer mirrors BuildDeck pattern: find-or-create per series/product,
rewards replaced wholesale on rerun (owned collection). 10 series,
270 products imported from seeds/sleeve-shop.json.

Controller:
- /sleeve/info returns wire-faithful dict-keyed shape
  ({sleeve_list: {<series_id>: {product_info: {<product_id>: ...}}}}).
  is_purchased_product derived from viewer.Sleeves.Contains(sleeve_id).
- /sleeve/buy: sales_type 0=free / 1=crystal / 2=rupy / 3=ticket(501).
  Validates series_product mismatch, currency, already-purchased.
  Currency debited with post-state-total reward_list entry; cosmetic
  grants dispatched through RewardGrantService.ApplyAsync (covers
  sleeve + emblem bundled grants per product).

476 tests pass (was 466; +10 sleeve tests).

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

SVSim.Database/Models/SleeveShopProductEntry.cs

@@ -0,0 +1,32 @@
+using SVSim.Database.Common;
+
+namespace SVSim.Database.Models;
+
+/// <summary>
+/// One purchasable sleeve product. PK = wire product_id (e.g. 301901). FK SeriesId.
+/// <para>
+/// Both <see cref="PriceCrystal"/> and <see cref="PriceRupy"/> are nullable. At least one must be
+/// populated for an enabled product (both zero = free, both null = invalid). Sleeves don't have
+/// the two-tier intro/regular pricing that BuildDeck products use — one price per currency.
+/// </para>
+/// <para>
+/// <see cref="Rewards"/> drives both the catalog display (in /sleeve/info) and the actual grant
+/// list (in /sleeve/buy). The capture shows each sleeve product grants a sleeve (type=6) and an
+/// emblem (type=7) — both faithful reward_detail_ids that exist in the cosmetic catalogs.
+/// </para>
+/// </summary>
+public class SleeveShopProductEntry : BaseEntity<int>
+{
+    public int SeriesId { get; set; }
+    /// <summary>Wire `name` field — SystemText key like "sleeve_138". Localised client-side.</summary>
+    public string NameKey { get; set; } = string.Empty;
+
+    public int? PriceCrystal { get; set; }
+    public int? PriceRupy { get; set; }
+
+    public bool IsEnabled { get; set; }
+
+    public List<SleeveShopProductRewardEntry> Rewards { get; set; } = new();
+
+    public SleeveShopSeriesEntry? Series { get; set; }
+}

SVSim.Database/Models/SleeveShopProductRewardEntry.cs

@@ -0,0 +1,17 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace SVSim.Database.Models;
+
+/// <summary>
+/// One per-buy reward attached to a sleeve product. Owned by <see cref="SleeveShopProductEntry"/>.
+/// Wire shape: one entry of the product-level `rewards` array in /sleeve/info. Order is
+/// preserved by <see cref="OrderIndex"/> since the wire shape is an ordered array, not a dict.
+/// </summary>
+[Owned]
+public class SleeveShopProductRewardEntry
+{
+    public int OrderIndex { get; set; }
+    public int RewardType { get; set; }   // Wizard.UserGoods.Type
+    public long RewardDetailId { get; set; }
+    public int RewardNumber { get; set; }
+}

SVSim.Database/Models/SleeveShopSeriesEntry.cs

@@ -0,0 +1,16 @@
+using SVSim.Database.Common;
+
+namespace SVSim.Database.Models;
+
+/// <summary>
+/// One sleeve-shop series (a themed collection — e.g. series 3019 "BattlePass sleeves",
+/// series 3004 "Granblue Fantasy collab"). PK = wire series_id. IsEnabled gates whether
+/// /sleeve/info renders this series.
+/// </summary>
+public class SleeveShopSeriesEntry : BaseEntity<int>
+{
+    public bool IsNew { get; set; }
+    public bool IsEnabled { get; set; }
+
+    public List<SleeveShopProductEntry> Products { get; set; } = new();
+}