feat(story): populate build/trial/default deck lists on get_deck_list

Wire IBuildDeckRepository into StoryService; GetDeckListAsync now looks
up the chapter's CharaId, fetches class-specific prebuilt/trial decks via
GetStoryDecksByClass, and loads all DefaultDecks for default_deck_list.
Class guard (1-8) leaves build/trial empty for non-class chapters, matching
prod behaviour.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Services/StoryService.cs

@@ -1,12 +1,16 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
+using System.Text.Json;
 using SVSim.Database;
 using SVSim.Database.Entities.Story;
 using SVSim.Database.Enums;
 using SVSim.Database.Models.Config;
 using SVSim.Database.Repositories.Deck;
+using SVSim.Database.Repositories.BuildDeck;
 using SVSim.Database.Services;
 using SVSim.Database.Repositories.Story;
+using SVSim.EmulatedEntrypoint.Models.Dtos;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Common;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Story;
 
 namespace SVSim.EmulatedEntrypoint.Services;
@@ -19,6 +23,7 @@ public class StoryService : IStoryService
     private readonly SVSimDbContext _db;
     private readonly IGameConfigService _configService;
     private readonly IDeckRepository _deckRepository;
+    private readonly IBuildDeckRepository _buildDecks;
     private readonly ILogger<StoryService> _logger;
 
     public StoryService(
@@ -28,6 +33,7 @@ public class StoryService : IStoryService
         SVSimDbContext db,
         IGameConfigService configService,
         IDeckRepository deckRepository,
+        IBuildDeckRepository buildDecks,
         ILogger<StoryService> logger)
     {
         _master = master;
@@ -36,6 +42,7 @@ public class StoryService : IStoryService
         _db = db;
         _configService = configService;
         _deckRepository = deckRepository;
+        _buildDecks = buildDecks;
         _logger = logger;
     }
 
@@ -344,16 +351,85 @@ public class StoryService : IStoryService
     {
         var byFormat = await _deckRepository.GetDecksByFormats(
             viewerId, new[] { SVSim.Database.Enums.Format.Rotation, SVSim.Database.Enums.Format.Unlimited });
-        return new GetDeckListResponse
+
+        var resp = new GetDeckListResponse
         {
             UserDeckRotation = byFormat[SVSim.Database.Enums.Format.Rotation]
-                .Select(d => new SVSim.EmulatedEntrypoint.Models.Dtos.UserDeck(d)).ToList(),
+                .Select(d => new UserDeck(d)).ToList(),
             UserDeckUnlimited = byFormat[SVSim.Database.Enums.Format.Unlimited]
-                .Select(d => new SVSim.EmulatedEntrypoint.Models.Dtos.UserDeck(d)).ToList(),
-            BuildDeckList = new List<BuildDeck>(),                  // v1: empty
+                .Select(d => new UserDeck(d)).ToList(),
             MaintenanceCardList = new List<long>(),
         };
+
+        // The chapter's leader (CharaId == class_id 1-8 for standard classes) drives which
+        // prebuilt/trial decks the story deck-select shows. Non-class chapters (custom leaders,
+        // chara_id outside 1-8) get empty build/trial lists, matching prod.
+        var chapter = await _master.GetChapterByIdAsync(storyId);
+        int classId = chapter?.CharaId ?? 0;
+        if (classId is >= 1 and <= 8)
+        {
+            var storyDecks = await _buildDecks.GetStoryDecksByClass(classId);
+            resp.BuildDeckList = storyDecks
+                .Where(d => d.Kind == StoryDeckKind.Build)
+                .Select(ToBuildDeck).ToList();
+            resp.TrialDeckList = storyDecks
+                .Where(d => d.Kind == StoryDeckKind.Trial)
+                .Select(ToTrialDeck).ToList();
+        }
+
+        // default_deck_list — all 8 starter decks, keyed by deck_no string (same shape as /deck/info).
+        var defaults = await _db.DefaultDecks.OrderBy(d => d.Id).ToListAsync();
+        resp.DefaultDeckList = defaults.ToDictionary(
+            d => d.Id.ToString(),
+            d => new DefaultDeck
+            {
+                DeckNo = d.DeckNo,
+                ClassId = d.ClassId,
+                SleeveId = d.SleeveId,
+                LeaderSkinId = d.LeaderSkinId,
+                DeckName = d.DeckName,
+                CardIdArray = JsonSerializer.Deserialize<List<long>>(d.CardIdArray) ?? new(),
+                IsCompleteDeck = 1,
+                IsAvailableDeck = 1,
+                MaintenanceCardIds = new(),
+            });
+
+        return resp;
     }
+
+    private static BuildDeck ToBuildDeck(StoryDeckView d) => new()
+    {
+        DeckNo = d.DeckNo,
+        OrderNum = d.OrderNum,
+        ClassId = d.ClassId,
+        SleeveId = d.SleeveId,
+        LeaderSkinId = d.LeaderSkinId,
+        EntryNo = d.EntryNo,
+        CreateDeckTime = null,
+        DeckName = d.DeckName,
+        CardIdArray = d.CardIdArray,
+        IsCompleteDeck = 1,
+        IsAvailableDeck = 1,
+        MaintenanceCardIds = new(),
+        IsRecommend = d.IsRecommend,
+    };
+
+    private static TrialDeck ToTrialDeck(StoryDeckView d) => new()
+    {
+        DeckNo = d.DeckNo,
+        ClassId = d.ClassId,
+        SleeveId = d.SleeveId,
+        LeaderSkinId = d.LeaderSkinId,
+        DeckName = d.DeckName,
+        CardIdArray = d.CardIdArray,
+        IsCompleteDeck = 1,
+        RestrictedCardExists = false,
+        IsAvailableDeck = 1,
+        MaintenanceCardIds = new(),
+        IsIncludeUnPossessionCard = false,
+        DeckFormat = d.DeckFormat ?? 0,
+        IsRecommend = d.IsRecommend,
+    };
     public async Task<StartResponse> StartAsync(StoryApiType apiType, int[] storyIds, long viewerId)
     {
         var resp = new StartResponse();