feat(arena-colosseum): 2-pick + curated deck sources (phase 3)

Closes the family. arena-colosseum 10/16 → 15/16 zero stubs (the 16th —
finish_load — is dead per project_dead_battle_endpoints).

* 2-Pick draft lift onto ArenaColosseumController:
  - get_candidate_classes samples from ArenaTwoPickConfig.AllowedClassIds
    and persists the slate onto the run.
  - class_choose accepts class_id XOR chaos_id; both populate run.ClassId,
    chaos branch stores ChaosId for replay.
  - get_candidate_cards is the idempotent draft-resume snapshot.
  - card_choose appends both cards from the picked pair, advances turn 1..15.
  - Pool override: ArenaTwoPickCardPoolService gets a non-breaking
    GeneratePickSetsForTurn(..., poolCardSetIds) overload; Colosseum routes
    pass ColosseumSeasonConfig.PoolCardSetIds (falls back to challenge →
    rotation when empty).
* Curated-deck schema: ColosseumHofDeck / ColosseumWindFallDeck /
  ColosseumAvatarDeck — three identical tables (separate per per-pool
  operational lifecycle), unique on DeckNo. Migration AddColosseumCuratedDecks.
* IColosseumCuratedDeck interface + a generic ColosseumCuratedDeckImporterBase<T>
  with three concrete subclasses (HOF / WindFall / Avatar), registered in
  Bootstrap. Seed files ship empty.
* 6 curated endpoints on ArenaColosseumController: get_{hof|windfall|avatar}_deck_list
  return BARE-ARRAY data per spec; register_{hof|windfall|avatar}_deck share
  one generic RegisterCuratedAsync<T> dispatcher. Cross-pool register
  rejected via per-pool lookup. Curated register has no is_published flag
  (constructed-only) — clears the run's flag for state consistency.
* Tests: 5 draft HTTP tests + 11 curated-deck HTTP tests (4 parameterized
  3 ways across HOF/WindFall/Avatar + a cross-pool isolation test + an
  is_published clear test). Existing TwoPick service tests updated for the
  new pool overload. Full suite: 1347/1347.

Phase 3 ship gate met. Branch ready for merge.

SVSim.Bootstrap/Importers/ColosseumCuratedDeckImporterBase.cs

@@ -0,0 +1,86 @@
+using Microsoft.EntityFrameworkCore;
+using SVSim.Database;
+using SVSim.Database.Models;
+
+namespace SVSim.Bootstrap.Importers;
+
+/// <summary>
+/// Shared upsert path for the three Colosseum curated-deck pools. Each subclass binds the
+/// EF entity type + the seed filename; the load + key + diff logic lives here. Empty seed
+/// files are non-fatal — the pools ship empty by default per the plan (admins fill them
+/// per-event).
+/// </summary>
+public abstract class ColosseumCuratedDeckImporterBase<TEntity>
+    where TEntity : class, IColosseumCuratedDeck, new()
+{
+    protected abstract string SeedFileName { get; }
+
+    public async Task<int> ImportAsync(SVSimDbContext context, string seedDir)
+    {
+        var path = Path.Combine(seedDir, SeedFileName);
+        if (!File.Exists(path))
+        {
+            Console.WriteLine($"[{GetType().Name}] missing {path}; skipping.");
+            return 0;
+        }
+
+        var seeds = SeedLoader.LoadList<ColosseumCuratedDeckSeed>(path);
+        var set = context.Set<TEntity>();
+        var existing = await set.ToDictionaryAsync(d => d.DeckNo);
+
+        int upserted = 0;
+        foreach (var s in seeds)
+        {
+            if (existing.TryGetValue(s.DeckNo, out var row))
+            {
+                row.ClassId = s.ClassId;
+                row.CardListJson = s.CardListJson;
+                row.SleeveId = s.SleeveId;
+                row.LeaderSkinId = s.LeaderSkinId;
+                row.DisplayOrder = s.DisplayOrder;
+            }
+            else
+            {
+                set.Add(new TEntity
+                {
+                    DeckNo = s.DeckNo,
+                    ClassId = s.ClassId,
+                    CardListJson = s.CardListJson,
+                    SleeveId = s.SleeveId,
+                    LeaderSkinId = s.LeaderSkinId,
+                    DisplayOrder = s.DisplayOrder,
+                });
+            }
+            upserted++;
+        }
+
+        await context.SaveChangesAsync();
+        Console.WriteLine($"[{GetType().Name}] upserted={upserted}");
+        return upserted;
+    }
+}
+
+public sealed class ColosseumCuratedDeckSeed
+{
+    public int DeckNo { get; set; }
+    public int ClassId { get; set; }
+    public string CardListJson { get; set; } = "[]";
+    public long SleeveId { get; set; }
+    public long LeaderSkinId { get; set; }
+    public int DisplayOrder { get; set; }
+}
+
+public sealed class ColosseumHofDecksImporter : ColosseumCuratedDeckImporterBase<ColosseumHofDeck>
+{
+    protected override string SeedFileName => "colosseum-hof-decks.json";
+}
+
+public sealed class ColosseumWindFallDecksImporter : ColosseumCuratedDeckImporterBase<ColosseumWindFallDeck>
+{
+    protected override string SeedFileName => "colosseum-windfall-decks.json";
+}
+
+public sealed class ColosseumAvatarDecksImporter : ColosseumCuratedDeckImporterBase<ColosseumAvatarDeck>
+{
+    protected override string SeedFileName => "colosseum-avatar-decks.json";
+}

SVSim.Bootstrap/Program.cs

@@ -85,6 +85,9 @@ public static class Program
             await new AvatarAbilityImporter().ImportAsync(context, opts.SeedDir);
             await new ArenaSeasonImporter().ImportAsync(context, opts.SeedDir);
             await new ArenaTwoPickRewardImporter().ImportAsync(context, opts.SeedDir);
+            await new ColosseumHofDecksImporter().ImportAsync(context, opts.SeedDir);
+            await new ColosseumWindFallDecksImporter().ImportAsync(context, opts.SeedDir);
+            await new ColosseumAvatarDecksImporter().ImportAsync(context, opts.SeedDir);
             await new BattlePassImporter().ImportAsync(context, opts.SeedDir);
             await new BattlePassSeasonImporter().ImportAsync(context, opts.SeedDir);
             await new BattlePassRewardImporter().ImportAsync(context, opts.SeedDir);