fix(guild): final-review remediation — replay_detail flat, FK on leader, transaction wraps, _db extraction

C1: replay_detail — flatten stored payload to data level. ChatReplayDetailTask.Parse() calls
new ReplayDetailInfo(data) which unguardedly accesses data[battleId], data[seed], data[vid1],
etc. Wrapping under replay_info key crashes the client. Controller now returns Ok(JsonElement)
directly so stored battle fields are at data root. Wire-shape test added.

C2: Guild.LeaderViewerId long to long?; add HasOne<Viewer> FK with OnDelete=SetNull; migration
AddGuildLeaderViewerIdFk; all consumers null-guarded with ?? 0L.

C3: BreakupAsync — wrap 6 destructive ops in IDbContextTransaction with InMemory fallback.

C4: CommitJoinAsync — wrap member-add + viewer-guildId-set + invite/request cleanup in
IDbContextTransaction with InMemory fallback. Chat event emitted after commit.

I1: GuildController — remove SVSimDbContext field; inject IViewerRepository + IGuildMemberRepository.
Add IGuildMemberRepository.GetViewerIdsInAGuildAsync (batch guild-membership check).
All _db.Viewers / _db.GuildMembers queries replaced with repo calls.

I2: GuildService — extract 3 _db.Viewers queries: GetEquippedEmblemIdAsync (CreateAsync),
LoadGuildProfileBatchAsync (ListOutgoingInvitesAsync + ListPendingJoinRequestsForMyGuildAsync).
Add GuildMemberProfile record with IsOfficialMarkDisplayed. GetEmblemListAsync for EmblemList.

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

SVSim.Database/Entities/Guild/Guild.cs

@@ -7,7 +7,7 @@ public class Guild
     public int GuildId { get; set; }                    // server-generated 9-digit
     public string Name { get; set; } = "";
     public string Description { get; set; } = "";
-    public long LeaderViewerId { get; set; }
+    public long? LeaderViewerId { get; set; }
     public long EmblemId { get; set; }
     public GuildActivity Activity { get; set; }
     public GuildJoinCondition JoinCondition { get; set; }

SVSim.Database/Migrations/20260627202442_AddGuildLeaderViewerIdFk.cs

@@ -0,0 +1,57 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace SVSim.Database.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddGuildLeaderViewerIdFk : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterColumn<long>(
+                name: "LeaderViewerId",
+                table: "Guilds",
+                type: "bigint",
+                nullable: true,
+                oldClrType: typeof(long),
+                oldType: "bigint");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Guilds_LeaderViewerId",
+                table: "Guilds",
+                column: "LeaderViewerId");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Guilds_Viewers_LeaderViewerId",
+                table: "Guilds",
+                column: "LeaderViewerId",
+                principalTable: "Viewers",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.SetNull);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Guilds_Viewers_LeaderViewerId",
+                table: "Guilds");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Guilds_LeaderViewerId",
+                table: "Guilds");
+
+            migrationBuilder.AlterColumn<long>(
+                name: "LeaderViewerId",
+                table: "Guilds",
+                type: "bigint",
+                nullable: false,
+                defaultValue: 0L,
+                oldClrType: typeof(long),
+                oldType: "bigint",
+                oldNullable: true);
+        }
+    }
+}

SVSim.Database/Migrations/SVSimDbContextModelSnapshot.cs

@@ -110,7 +110,7 @@ namespace SVSim.Database.Migrations
                     b.Property<int>("JoinCondition")
                         .HasColumnType("integer");
 
-                    b.Property<long>("LeaderViewerId")
+                    b.Property<long?>("LeaderViewerId")
                         .HasColumnType("bigint");
 
                     b.Property<string>("Name")
@@ -120,6 +120,8 @@ namespace SVSim.Database.Migrations
 
                     b.HasKey("GuildId");
 
+                    b.HasIndex("LeaderViewerId");
+
                     b.HasIndex("Name");
 
                     b.ToTable("Guilds");
@@ -3653,6 +3655,14 @@ namespace SVSim.Database.Migrations
                         .IsRequired();
                 });
 
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.Guild", b =>
+                {
+                    b.HasOne("SVSim.Database.Models.Viewer", null)
+                        .WithMany()
+                        .HasForeignKey("LeaderViewerId")
+                        .OnDelete(DeleteBehavior.SetNull);
+                });
+
             modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildChatMessage", b =>
                 {
                     b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")

SVSim.Database/Repositories/Guild/GuildMemberRepository.cs

@@ -70,4 +70,15 @@ public sealed class GuildMemberRepository : IGuildMemberRepository
             result[row.GuildId] = row.Count;
         return result;
     }
+
+    public async Task<HashSet<long>> GetViewerIdsInAGuildAsync(
+        IReadOnlyList<long> viewerIds, CancellationToken ct = default)
+    {
+        if (viewerIds.Count == 0) return new HashSet<long>();
+        var ids = await _db.GuildMembers
+            .Where(m => viewerIds.Contains(m.ViewerId))
+            .Select(m => m.ViewerId)
+            .ToListAsync(ct);
+        return new HashSet<long>(ids);
+    }
 }

SVSim.Database/Repositories/Guild/IGuildMemberRepository.cs

@@ -15,4 +15,11 @@ public interface IGuildMemberRepository
 
     /// <summary>Returns a count of members per guild for the given guild ids. Used by Task 9 search.</summary>
     Task<Dictionary<int, int>> CountBatchByGuildIdsAsync(IReadOnlyList<int> guildIds, CancellationToken ct = default);
+
+    /// <summary>
+    /// Batch-checks whether each viewer id in <paramref name="viewerIds"/> is currently in any guild.
+    /// Returns a set of viewer ids that ARE in a guild. Used by <c>/guild/friend_list</c> to set
+    /// <c>is_join_guild</c>.
+    /// </summary>
+    Task<HashSet<long>> GetViewerIdsInAGuildAsync(IReadOnlyList<long> viewerIds, CancellationToken ct = default);
 }

SVSim.Database/Repositories/Viewer/IViewerRepository.cs

@@ -13,6 +13,18 @@ public record ChatUserProfile(
     int    Rank,
     int    DegreeId);
 
+/// <summary>
+/// Richer profile shape used by guild management surfaces (invite list, join-request list).
+/// Extends <see cref="ChatUserProfile"/> with <c>IsOfficialMarkDisplayed</c>.
+/// </summary>
+public record GuildMemberProfile(
+    string Name,
+    long   EmblemId,
+    string CountryCode,
+    int    Rank,
+    int    DegreeId,
+    bool   IsOfficialMarkDisplayed);
+
 public interface IViewerRepository
 {
     Task<Models.Viewer?> GetViewerBySocialConnection(SocialAccountType accountType, ulong socialId);
@@ -57,4 +69,23 @@ public interface IViewerRepository
     /// in the controller. Ids with no matching row are absent from the result. Read-only (AsNoTracking).
     /// </summary>
     Task<IReadOnlyDictionary<long, ChatUserProfile>> LoadChatProfilesAsync(IReadOnlyCollection<long> viewerIds, CancellationToken ct = default);
+
+    /// <summary>
+    /// Batch-loads the <see cref="GuildMemberProfile"/> fields (emblem, degree,
+    /// <c>IsOfficialMarkDisplayed</c>) for a set of viewer ids. Used by guild management surfaces
+    /// (invite_user_list, join_request_list). Ids with no matching row are absent. Read-only.
+    /// </summary>
+    Task<IReadOnlyDictionary<long, GuildMemberProfile>> LoadGuildProfileBatchAsync(IReadOnlyCollection<long> viewerIds, CancellationToken ct = default);
+
+    /// <summary>
+    /// Loads a viewer's currently-equipped emblem id, or <c>100_000_000</c> (default) if none.
+    /// Used by <see cref="SVSim.Database.Services.Guild.GuildService"/> to seed the guild's initial emblem.
+    /// Returns <c>100_000_000</c> if the viewer doesn't exist.
+    /// </summary>
+    Task<long> GetEquippedEmblemIdAsync(long viewerId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Batch-loads owned guild-emblem ids for a viewer. Used by <c>/guild/emblem_list</c>.
+    /// </summary>
+    Task<List<long>> GetEmblemListAsync(long viewerId, CancellationToken ct = default);
 }

SVSim.Database/Repositories/Viewer/ViewerRepository.cs

@@ -323,6 +323,56 @@ public class ViewerRepository : IViewerRepository
                 DegreeId:    r.DegreeId));
     }
 
+    public async Task<IReadOnlyDictionary<long, GuildMemberProfile>> LoadGuildProfileBatchAsync(IReadOnlyCollection<long> viewerIds, CancellationToken ct = default)
+    {
+        if (viewerIds.Count == 0) return new Dictionary<long, GuildMemberProfile>();
+        var rows = await _dbContext.Set<Models.Viewer>()
+            .AsNoTracking()
+            .Include(v => v.Info.SelectedEmblem)
+            .Include(v => v.Info.SelectedDegree)
+            .Where(v => viewerIds.Contains(v.Id))
+            .Select(v => new
+            {
+                v.Id,
+                v.DisplayName,
+                EmblemId               = v.Info.SelectedEmblem != null ? v.Info.SelectedEmblem.Id : 100_000_000L,
+                CountryCode            = v.Info.CountryCode ?? "",
+                DegreeId               = v.Info.SelectedDegree != null ? (int)v.Info.SelectedDegree.Id : 0,
+                IsOfficialMarkDisplayed = v.Info.IsOfficialMarkDisplayed,
+            })
+            .ToListAsync(ct);
+        return rows.ToDictionary(
+            r => r.Id,
+            r => new GuildMemberProfile(
+                Name:                   r.DisplayName,
+                EmblemId:               r.EmblemId,
+                CountryCode:            r.CountryCode,
+                Rank:                   1, // TODO: real rank when rank tracking lands
+                DegreeId:               r.DegreeId,
+                IsOfficialMarkDisplayed: r.IsOfficialMarkDisplayed));
+    }
+
+    public async Task<long> GetEquippedEmblemIdAsync(long viewerId, CancellationToken ct = default)
+    {
+        var row = await _dbContext.Set<Models.Viewer>()
+            .AsNoTracking()
+            .Include(v => v.Info.SelectedEmblem)
+            .Where(v => v.Id == viewerId)
+            .Select(v => new { EmblemId = v.Info.SelectedEmblem != null ? v.Info.SelectedEmblem.Id : 100_000_000L })
+            .FirstOrDefaultAsync(ct);
+        return row?.EmblemId ?? 100_000_000L;
+    }
+
+    public async Task<List<long>> GetEmblemListAsync(long viewerId, CancellationToken ct = default)
+    {
+        var viewer = await _dbContext.Set<Models.Viewer>()
+            .AsNoTracking()
+            .Include(v => v.Emblems)
+            .Where(v => v.Id == viewerId)
+            .FirstOrDefaultAsync(ct);
+        return viewer?.Emblems.Select(e => (long)e.Id).ToList() ?? new List<long>();
+    }
+
     private async Task<Models.Viewer> BuildDefaultViewer(string displayName, int initialTutorialState = 1)
     {
         Models.Viewer viewer = new Models.Viewer

SVSim.Database/SVSimDbContext.cs

@@ -520,6 +520,9 @@ public class SVSimDbContext : DbContext
             e.Property(g => g.Name).HasMaxLength(64);
             e.Property(g => g.Description).HasMaxLength(512);
             e.HasIndex(g => g.Name);                              // name search
+            e.HasOne<Viewer>().WithMany()
+                .HasForeignKey(g => g.LeaderViewerId)
+                .OnDelete(DeleteBehavior.SetNull);
         });
 
         modelBuilder.Entity<GuildMember>(e =>

SVSim.Database/Services/Guild/GuildService.cs

@@ -1,4 +1,5 @@
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage;
 using SVSim.Database.Entities.Guild;
 using SVSim.Database.Models.Config;
 using SVSim.Database.Repositories.Guild;
@@ -67,9 +68,9 @@ public sealed class GuildService : IGuildService
         var rows = await _guilds.SearchAsync(name ?? "", activity, joinCondition, memberBucket, cfg.MaxMemberNum, cfg.SearchResultCap, ct);
         var guildIds = rows.Select(r => r.GuildId).ToList();
         var memberCounts = await _members.CountBatchByGuildIdsAsync(guildIds, ct);
-        var leaderIds = rows.Select(r => r.LeaderViewerId).Distinct().ToList();
+        var leaderIds = rows.Select(r => r.LeaderViewerId).Where(id => id.HasValue).Select(id => id!.Value).Distinct().ToList();
         var leaderNames = await _viewers.LoadDisplayNamesAsync(leaderIds, ct);
-        return rows.Select(r => new GuildSearchEntry(r, memberCounts.GetValueOrDefault(r.GuildId, 0), leaderNames.GetValueOrDefault(r.LeaderViewerId, ""))).ToList();
+        return rows.Select(r => new GuildSearchEntry(r, memberCounts.GetValueOrDefault(r.GuildId, 0), leaderNames.GetValueOrDefault(r.LeaderViewerId ?? 0L, ""))).ToList();
     }
 
     public async Task<GuildOpResult> CreateAsync(long viewerId, CreateGuildRequest req, CancellationToken ct = default)
@@ -86,10 +87,9 @@ public sealed class GuildService : IGuildService
         if (await _guilds.NameExistsAsync(req.Name, ct))
             return new(GuildOpResultCode.NameTaken);
 
-        var viewer = await _db.Viewers
+        // Load the viewer's equipped emblem to use as the guild's initial emblem.
-            .Include(v => v.Info.SelectedEmblem)
+        // If the viewer doesn't exist (shouldn't happen post-auth), returns 100_000_000 default.
-            .FirstOrDefaultAsync(v => v.Id == viewerId, ct);
+        long viewerEmblemId = await _viewers.GetEquippedEmblemIdAsync(viewerId, ct);
-        if (viewer is null) return new(GuildOpResultCode.PermissionDenied);
 
         var id = await _idGen.NextAsync(
             (cand, c) => _guilds.GetByIdAsync(cand, c).ContinueWith(t => t.Result is not null, c),
@@ -101,7 +101,7 @@ public sealed class GuildService : IGuildService
             Name = req.Name,
             Description = "",
             LeaderViewerId = viewerId,
-            EmblemId = DefaultEmblemId(viewer),
+            EmblemId = viewerEmblemId,
             Activity = (GuildActivity)req.Activity,
             JoinCondition = (GuildJoinCondition)req.JoinCondition,
             CreatedAt = now,
@@ -116,22 +116,12 @@ public sealed class GuildService : IGuildService
         await _joinRequests.CancelPendingForViewerAsync(viewerId, now, ct);
 
         // Update Viewer.GuildId pointer for quick lookups.
-        viewer.GuildId = id;
+        await _viewers.SetGuildIdAsync(viewerId, id, ct);
-        await _db.SaveChangesAsync(ct);
 
         await _chat.EmitSystemEventAsync(id, viewerId, GuildChatMessageType.CreateGuild, body: null, ct);
         return new(GuildOpResultCode.Ok, GuildId: id);
     }
 
-    /// <summary>
-    /// Returns the viewer's currently-equipped emblem id, or 100000000 (default) if none.
-    /// </summary>
-    private static long DefaultEmblemId(Models.Viewer viewer)
-    {
-        var emblemId = viewer.Info?.SelectedEmblem?.Id;
-        return emblemId is > 0 ? emblemId.Value : 100_000_000L;
-    }
-
     public async Task<GuildOpResult> UpdateAsync(long viewerId, UpdateGuildRequest req, CancellationToken ct = default)
     {
         var m = await _members.GetMembershipAsync(viewerId, ct);
@@ -177,17 +167,33 @@ public sealed class GuildService : IGuildService
         if (membership is null) return new(GuildOpResultCode.NotInGuild);
         if (membership.Role != GuildRole.Leader) return new(GuildOpResultCode.PermissionDenied);
 
-        var now = DateTime.UtcNow;
+        IDbContextTransaction? tx = null;
-        var members = await _members.ListByGuildAsync(membership.GuildId, ct);
+        try
-        foreach (var m in members) await _viewers.ClearGuildIdAsync(m.ViewerId, ct);
+        {
+            try { tx = await _db.Database.BeginTransactionAsync(ct); } catch (InvalidOperationException) { /* InMemory provider */ }
 
-        await _chatMessages.DeleteAllForGuildAsync(membership.GuildId, ct);
+            var now = DateTime.UtcNow;
-        await _invites.DeleteAllForGuildAsync(membership.GuildId, ct);
+            var members = await _members.ListByGuildAsync(membership.GuildId, ct);
-        await _joinRequests.DeleteAllForGuildAsync(membership.GuildId, ct);
+            foreach (var m in members) await _viewers.ClearGuildIdAsync(m.ViewerId, ct);
-        await _members.DeleteAllForGuildAsync(membership.GuildId, ct);
-        await _guilds.MarkBrokenUpAsync(membership.GuildId, now, ct);
 
-        return GuildOpResult.Ok;
+            await _chatMessages.DeleteAllForGuildAsync(membership.GuildId, ct);
+            await _invites.DeleteAllForGuildAsync(membership.GuildId, ct);
+            await _joinRequests.DeleteAllForGuildAsync(membership.GuildId, ct);
+            await _members.DeleteAllForGuildAsync(membership.GuildId, ct);
+            await _guilds.MarkBrokenUpAsync(membership.GuildId, now, ct);
+
+            if (tx != null) await tx.CommitAsync(ct);
+            return GuildOpResult.Ok;
+        }
+        catch
+        {
+            if (tx != null) await tx.RollbackAsync(ct);
+            throw;
+        }
+        finally
+        {
+            tx?.Dispose();
+        }
     }
 
     public async Task<GuildOpResult> InviteAsync(long callerViewerId, long targetViewerId, CancellationToken ct = default)
@@ -305,12 +311,31 @@ public sealed class GuildService : IGuildService
 
     private async Task CommitJoinAsync(long viewerId, int guildId, DateTime now, CancellationToken ct)
     {
-        await _members.AddAsync(
+        IDbContextTransaction? tx = null;
-            new GuildMember { GuildId = guildId, ViewerId = viewerId, Role = GuildRole.Regular, JoinedAt = now },
+        try
-            ct);
+        {
-        await _viewers.SetGuildIdAsync(viewerId, guildId, ct);
+            try { tx = await _db.Database.BeginTransactionAsync(ct); } catch (InvalidOperationException) { /* InMemory provider */ }
-        await _invites.ConsumePendingForViewerAsync(viewerId, now, ct);
+
-        await _joinRequests.CancelPendingForViewerAsync(viewerId, now, ct);
+            await _members.AddAsync(
+                new GuildMember { GuildId = guildId, ViewerId = viewerId, Role = GuildRole.Regular, JoinedAt = now },
+                ct);
+            await _viewers.SetGuildIdAsync(viewerId, guildId, ct);
+            await _invites.ConsumePendingForViewerAsync(viewerId, now, ct);
+            await _joinRequests.CancelPendingForViewerAsync(viewerId, now, ct);
+
+            if (tx != null) await tx.CommitAsync(ct);
+        }
+        catch
+        {
+            if (tx != null) await tx.RollbackAsync(ct);
+            throw;
+        }
+        finally
+        {
+            tx?.Dispose();
+        }
+
+        // Emit chat event outside the transaction — chat failure doesn't roll back the join.
         await _chat.EmitSystemEventAsync(guildId, viewerId, GuildChatMessageType.Join, body: null, ct);
     }
 
@@ -470,28 +495,20 @@ public sealed class GuildService : IGuildService
         if (pendingInvites.Count == 0) return Array.Empty<GuildOutgoingInviteEntry>();
 
         var inviteeIds = pendingInvites.Select(i => i.InviteeViewerId).Distinct().ToList();
-        var names = await _viewers.LoadDisplayNamesAsync(inviteeIds, ct);
+        var profiles = await _viewers.LoadGuildProfileBatchAsync(inviteeIds, ct);
-
-        // Load emblem + degree data for invitees.
-        var viewerRows = await _db.Viewers
-            .AsNoTracking()
-            .Include(v => v.Info.SelectedEmblem)
-            .Include(v => v.Info.SelectedDegree)
-            .Where(v => inviteeIds.Contains(v.Id))
-            .ToDictionaryAsync(v => v.Id, ct);
 
         var result = new List<GuildOutgoingInviteEntry>(pendingInvites.Count);
         foreach (var invite in pendingInvites)
         {
-            viewerRows.TryGetValue(invite.InviteeViewerId, out var v);
+            profiles.TryGetValue(invite.InviteeViewerId, out var p);
             result.Add(new GuildOutgoingInviteEntry(
                 InviteId: invite.Id,
                 InviteeViewerId: invite.InviteeViewerId,
-                Name: names.GetValueOrDefault(invite.InviteeViewerId, ""),
+                Name: p?.Name ?? "",
-                EmblemId: v?.Info?.SelectedEmblem?.Id is > 0 ? v.Info.SelectedEmblem.Id : 100_000_000L,
+                EmblemId: p?.EmblemId ?? 100_000_000L,
-                CountryCode: v?.Info?.CountryCode ?? "",
+                CountryCode: p?.CountryCode ?? "",
-                Rank: 1,
+                Rank: p?.Rank ?? 1,
-                DegreeId: v?.Info?.SelectedDegree?.Id ?? 0,
+                DegreeId: p?.DegreeId ?? 0,
                 CreatedAt: invite.CreatedAt));
         }
         return result;
@@ -505,14 +522,14 @@ public sealed class GuildService : IGuildService
 
         var guildIds = pendingInvites.Select(i => i.GuildId).Distinct().ToList();
         var memberCounts = await _members.CountBatchByGuildIdsAsync(guildIds, ct);
-        var leaderIds = pendingInvites.Select(i => i.Guild.LeaderViewerId).Distinct().ToList();
+        var leaderIds = pendingInvites.Select(i => i.Guild.LeaderViewerId).Where(id => id.HasValue).Select(id => id!.Value).Distinct().ToList();
         var leaderNames = await _viewers.LoadDisplayNamesAsync(leaderIds, ct);
 
         return pendingInvites.Select(invite => new GuildReceivedInviteEntry(
             InviteId: invite.Id,
             Guild: invite.Guild,
             MemberNum: memberCounts.GetValueOrDefault(invite.GuildId, 0),
-            LeaderName: leaderNames.GetValueOrDefault(invite.Guild.LeaderViewerId, ""))).ToList();
+            LeaderName: leaderNames.GetValueOrDefault(invite.Guild.LeaderViewerId ?? 0L, ""))).ToList();
     }
 
     public async Task<IReadOnlyList<GuildJoinRequestEntry>> ListPendingJoinRequestsForMyGuildAsync(long viewerId, CancellationToken ct = default)
@@ -527,26 +544,19 @@ public sealed class GuildService : IGuildService
         if (requests.Count == 0) return Array.Empty<GuildJoinRequestEntry>();
 
         var applicantIds = requests.Select(r => r.ViewerId).Distinct().ToList();
-        var names = await _viewers.LoadDisplayNamesAsync(applicantIds, ct);
+        var profiles = await _viewers.LoadGuildProfileBatchAsync(applicantIds, ct);
-
-        var viewerRows = await _db.Viewers
-            .AsNoTracking()
-            .Include(v => v.Info.SelectedEmblem)
-            .Include(v => v.Info.SelectedDegree)
-            .Where(v => applicantIds.Contains(v.Id))
-            .ToDictionaryAsync(v => v.Id, ct);
 
         return requests.Select(r =>
         {
-            viewerRows.TryGetValue(r.ViewerId, out var v);
+            profiles.TryGetValue(r.ViewerId, out var p);
             return new GuildJoinRequestEntry(
                 ApplicantViewerId: r.ViewerId,
-                Name: names.GetValueOrDefault(r.ViewerId, ""),
+                Name: p?.Name ?? "",
-                EmblemId: v?.Info?.SelectedEmblem?.Id is > 0 ? v.Info.SelectedEmblem.Id : 100_000_000L,
+                EmblemId: p?.EmblemId ?? 100_000_000L,
-                CountryCode: v?.Info?.CountryCode ?? "",
+                CountryCode: p?.CountryCode ?? "",
-                Rank: 1,
+                Rank: p?.Rank ?? 1,
-                DegreeId: v?.Info?.SelectedDegree?.Id ?? 0,
+                DegreeId: p?.DegreeId ?? 0,
-                IsOfficialMarkDisplayed: v?.Info?.IsOfficialMarkDisplayed == true,
+                IsOfficialMarkDisplayed: p?.IsOfficialMarkDisplayed ?? false,
                 RequestedAt: r.CreatedAt);
         }).ToList();
     }

SVSim.EmulatedEntrypoint/Controllers/GuildChatController.cs

@@ -131,15 +131,19 @@ public sealed class GuildChatController : SVSimController
     }
 
     [HttpPost("replay_detail")]
-    public async Task<ActionResult<GuildChatReplayDetailResponse>> ReplayDetail([FromBody] GuildChatReplayDetailRequest req, CancellationToken ct)
+    public async Task<ActionResult> ReplayDetail([FromBody] GuildChatReplayDetailRequest req, CancellationToken ct)
     {
         if (!TryGetViewerId(out var viewerId)) return Unauthorized();
 
         var payloadJson = await _chat.GetReplayDetailAsync(viewerId, (int)req.MessageId, ct);
         if (payloadJson is null) return Ok(new { result_code = 2 });
 
-        var replayInfo = ParseJsonElementOrNull(payloadJson);
+        // ReplayDetailInfo(data) accesses data["battleId"], data["seed"], data["vid1"], etc.
-        return new GuildChatReplayDetailResponse { ReplayInfo = replayInfo };
+        // directly without Keys.Contains guards — returning a wrapper object crashes the client.
+        // The stored ReplayPayload IS the full flat battle object; emit its fields directly as
+        // the data payload so data["battleId"].ToLong() etc. resolve correctly.
+        var replayElement = ParseJsonElementOrNull(payloadJson);
+        return replayElement.HasValue ? Ok(replayElement.Value) : Ok(new { result_code = 2 });
     }
 
     [HttpPost("deck_log")]

SVSim.EmulatedEntrypoint/Controllers/GuildController.cs

@@ -1,9 +1,8 @@
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.EntityFrameworkCore;
-using SVSim.Database;
 using SVSim.Database.Entities.Guild;
-using SVSim.Database.Models;
 using SVSim.Database.Models.Config;
+using SVSim.Database.Repositories.Guild;
+using SVSim.Database.Repositories.Viewer;
 using SVSim.Database.Services;
 using SVSim.Database.Services.Friend;
 using SVSim.Database.Services.Guild;
@@ -20,17 +19,24 @@ public sealed class GuildController : SVSimController
 {
     private readonly IGuildService _guild;
     private readonly IGameConfigService _configs;
-    private readonly SVSimDbContext _db;
+    private readonly IViewerRepository _viewers;
+    private readonly IGuildMemberRepository _members;
     private readonly IFriendService _friends;
 
     // Wire error code returned when guild operations fail (non-1 result_code).
     private const int GuildErrorResultCode = 2;
 
-    public GuildController(IGuildService guild, IGameConfigService configs, SVSimDbContext db, IFriendService friends)
+    public GuildController(
+        IGuildService guild,
+        IGameConfigService configs,
+        IViewerRepository viewers,
+        IGuildMemberRepository members,
+        IFriendService friends)
     {
         _guild = guild;
         _configs = configs;
-        _db = db;
+        _viewers = viewers;
+        _members = members;
         _friends = friends;
     }
 
@@ -56,7 +62,7 @@ public sealed class GuildController : SVSimController
             resp.JoinRequestCount = view.JoinRequestCount;
             resp.InviteCount = view.InviteCount;
             var memberDtos = await ToMemberDtoListAsync(view.Members, viewerId, ct);
-            var leaderName = memberDtos.FirstOrDefault(m => m.ViewerId == view.Guild.LeaderViewerId)?.Name ?? "";
+            var leaderName = memberDtos.FirstOrDefault(m => m.ViewerId == (view.Guild.LeaderViewerId ?? 0L))?.Name ?? "";
             resp.Guild = new GuildBundle
             {
                 Detail = ToDetailDto(view.Guild, view.Members.Count, leaderName),
@@ -95,14 +101,17 @@ public sealed class GuildController : SVSimController
         var r = await _guild.UpdateAsync(viewerId, new(activity, joinCondition, name), ct);
         if (!r.IsOk) return WireError();
 
-        var m = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
+        var m = await _members.GetMembershipAsync(viewerId, ct);
         if (m is null) return WireError();
         var guild = await _guild.GetActiveAsync(m.GuildId, ct);
         if (guild is null) return WireError();
-        var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
+        var memberCount = await _members.CountByGuildAsync(guild.GuildId, ct);
-        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
+        var leaderNames = guild.LeaderViewerId.HasValue
+            ? await _viewers.LoadDisplayNamesAsync(new[] { guild.LeaderViewerId.Value }, ct)
+            : new Dictionary<long, string>();
+        var leaderName = leaderNames.GetValueOrDefault(guild.LeaderViewerId ?? 0L, "");
         // GuildUpdateTask.Parse() reads data["guild"] directly as GuildDetailInfo — flat, no "detail" wrapper.
-        return new GuildUpdateResponse { Guild = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") };
+        return new GuildUpdateResponse { Guild = ToDetailDto(guild, memberCount, leaderName) };
     }
 
     [HttpPost("update_description")]
@@ -120,16 +129,19 @@ public sealed class GuildController : SVSimController
         var r = await _guild.UpdateEmblemAsync(viewerId, req.EmblemId, ct);
         if (!r.IsOk) return WireError();
 
-        var m = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
+        var m = await _members.GetMembershipAsync(viewerId, ct);
         if (m is null) return WireError();
         var guild = await _guild.GetActiveAsync(m.GuildId, ct);
         if (guild is null) return WireError();
-        var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
+        var memberCount = await _members.CountByGuildAsync(guild.GuildId, ct);
-        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
+        var leaderNames2 = guild.LeaderViewerId.HasValue
+            ? await _viewers.LoadDisplayNamesAsync(new[] { guild.LeaderViewerId.Value }, ct)
+            : new Dictionary<long, string>();
+        var leaderName2 = leaderNames2.GetValueOrDefault(guild.LeaderViewerId ?? 0L, "");
         // GuildEmblemUpdateTask.Parse() reads data["guild"]["detail"] — nested wrapper required.
         return new GuildUpdateEmblemResponse
         {
-            Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") }
+            Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leaderName2) }
         };
     }
 
@@ -145,14 +157,10 @@ public sealed class GuildController : SVSimController
     public async Task<ActionResult<GuildEmblemListResponse>> EmblemList([FromBody] BaseRequest _, CancellationToken ct)
     {
         if (!TryGetViewerId(out var viewerId)) return Unauthorized();
-        var viewer = await _db.Viewers
+        var emblemIds = await _viewers.GetEmblemListAsync(viewerId, ct);
-            .AsNoTracking()
-            .Include(v => v.Emblems)
-            .FirstOrDefaultAsync(v => v.Id == viewerId, ct);
-        var emblems = viewer?.Emblems ?? new();
         return new GuildEmblemListResponse
         {
-            EmblemList = emblems.Select(e => new GuildEmblemEntry { EmblemId = e.Id }).ToList()
+            EmblemList = emblemIds.Select(id => new GuildEmblemEntry { EmblemId = id }).ToList()
         };
     }
 
@@ -162,13 +170,16 @@ public sealed class GuildController : SVSimController
         if (!TryGetViewerId(out _)) return Unauthorized();
         var guild = await _guild.GetActiveAsync(req.GuildId, ct);
         if (guild is null) return new GuildOthersInfoResponse();
-        var memberCount = await _db.GuildMembers.CountAsync(m => m.GuildId == guild.GuildId, ct);
+        var memberCount = await _members.CountByGuildAsync(guild.GuildId, ct);
-        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
+        var othersLeaderNames = guild.LeaderViewerId.HasValue
+            ? await _viewers.LoadDisplayNamesAsync(new[] { guild.LeaderViewerId.Value }, ct)
+            : new Dictionary<long, string>();
+        var othersLeaderName = othersLeaderNames.GetValueOrDefault(guild.LeaderViewerId ?? 0L, "");
         return new GuildOthersInfoResponse
         {
             Guild = new GuildDetailSubTree
             {
-                Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "")
+                Detail = ToDetailDto(guild, memberCount, othersLeaderName)
             }
         };
     }
@@ -184,16 +195,11 @@ public sealed class GuildController : SVSimController
 
         // For each friend, determine if they are already in a guild (is_join_guild).
         var friendViewerIds = friendInfo.Friends.Select(f => (long)f.ViewerId).ToList();
-        var viewerRows = await _db.Viewers
+        var inGuild = await _members.GetViewerIdsInAGuildAsync(friendViewerIds, ct);
-            .AsNoTracking()
-            .Where(v => friendViewerIds.Contains(v.Id))
-            .Select(v => new { v.Id, v.GuildId })
-            .ToDictionaryAsync(v => v.Id, v => v.GuildId, ct);
 
         var candidates = new List<GuildInviteCandidateDto>(friendInfo.Friends.Count);
         foreach (var f in friendInfo.Friends)
         {
-            viewerRows.TryGetValue(f.ViewerId, out var guildId);
             candidates.Add(new GuildInviteCandidateDto
             {
                 ViewerId    = f.ViewerId,
@@ -202,7 +208,7 @@ public sealed class GuildController : SVSimController
                 CountryCode = f.CountryCode,
                 Rank        = f.Rank,
                 DegreeId    = f.DegreeId,
-                IsJoinGuild = guildId is not null,
+                IsJoinGuild = inGuild.Contains(f.ViewerId),
             });
         }
 
@@ -247,7 +253,7 @@ public sealed class GuildController : SVSimController
                 Activity = (int)e.Guild.Activity,
                 MemberNum = e.MemberNum,
                 LeaderName = e.LeaderName,
-                LeaderViewerId = e.Guild.LeaderViewerId,
+                LeaderViewerId = e.Guild.LeaderViewerId ?? 0L,
                 InviteId = e.InviteId,
             }).ToList(),
         };
@@ -357,12 +363,10 @@ public sealed class GuildController : SVSimController
         if (!r.IsOk) return WireError();
 
         // Load caller's membership to get the guild id, then return the full updated member list.
-        var membership = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
+        var membership = await _members.GetMembershipAsync(viewerId, ct);
         if (membership is null) return WireError();
 
-        var members = await _db.GuildMembers
+        var members = await _members.ListByGuildAsync(membership.GuildId, ct);
-            .Where(m => m.GuildId == membership.GuildId)
-            .ToListAsync(ct);
 
         var memberDtos = await ToMemberDtoListAsync(members, viewerId, ct);
         return new GuildChangeRoleResponse { Members = memberDtos };
@@ -379,7 +383,7 @@ public sealed class GuildController : SVSimController
         JoinCondition = (int)guild.JoinCondition,
         Activity = (int)guild.Activity,
         MemberNum = memberCount,
-        LeaderViewerId = guild.LeaderViewerId,
+        LeaderViewerId = guild.LeaderViewerId ?? 0L,
         LeaderName = leaderName,
     };
 
@@ -391,33 +395,26 @@ public sealed class GuildController : SVSimController
         if (members.Count == 0) return new();
 
         var viewerIds = members.Select(m => m.ViewerId).ToList();
-
+        var profiles = await _viewers.LoadGuildProfileBatchAsync(viewerIds, ct);
-        // Batch-load viewer rows with Info + SelectedEmblem + SelectedDegree.
-        var viewers = await _db.Viewers
-            .AsNoTracking()
-            .Include(v => v.Info.SelectedEmblem)
-            .Include(v => v.Info.SelectedDegree)
-            .Where(v => viewerIds.Contains(v.Id))
-            .ToDictionaryAsync(v => v.Id, ct);
 
         var result = new List<GuildMemberInfoDto>(members.Count);
         foreach (var m in members)
         {
-            viewers.TryGetValue(m.ViewerId, out var v);
+            profiles.TryGetValue(m.ViewerId, out var p);
-            result.Add(ToMemberDto(m, v));
+            result.Add(ToMemberDto(m, p));
         }
         return result;
     }
 
-    private static GuildMemberInfoDto ToMemberDto(GuildMember member, Viewer? viewer) => new()
+    private static GuildMemberInfoDto ToMemberDto(GuildMember member, GuildMemberProfile? profile) => new()
     {
         ViewerId = member.ViewerId,
-        Name = viewer?.DisplayName ?? "",
+        Name = profile?.Name ?? "",
-        EmblemId = viewer?.Info?.SelectedEmblem?.Id is > 0 ? viewer.Info.SelectedEmblem.Id : 100_000_000L,
+        EmblemId = profile?.EmblemId ?? 100_000_000L,
-        CountryCode = viewer?.Info?.CountryCode ?? "",
+        CountryCode = profile?.CountryCode ?? "",
-        Rank = 1,            // TODO: populate from actual rank data when rank tracking lands
+        Rank = profile?.Rank ?? 1,
-        DegreeId = viewer?.Info?.SelectedDegree?.Id ?? 0,
+        DegreeId = profile?.DegreeId ?? 0,
-        IsOfficialMarkDisplayed = viewer?.Info?.IsOfficialMarkDisplayed == true ? 1 : 0,
+        IsOfficialMarkDisplayed = profile?.IsOfficialMarkDisplayed == true ? 1 : 0,
         Role = (int)member.Role,
     };
 

SVSim.EmulatedEntrypoint/Models/Dtos/GuildChat/GuildChatReplayDetailResponse.cs

@@ -1,22 +1,32 @@
-using MessagePack;
-using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace SVSim.EmulatedEntrypoint.Models.Dtos.GuildChat;
 
 /// <summary>
 /// Response for POST /guild_chat/replay_detail.
-/// Shape is opaque pending replay-subsystem documentation.
+///
-/// TODO(post-merge): enumerate fields from Wizard/ReplayDetailInfo.cs when replay subsystem is documented.
+/// Wire shape: the stored ReplayPayload JSON is forwarded FLAT as the entire data payload.
-/// Using JsonElement pass-through so the stored ReplayPayload JSON is forwarded verbatim.
+/// ChatReplayDetailTask.Parse() calls new ReplayDetailInfo(base.ResponseData["data"]) which
+/// then accesses data["battleId"], data["seed"], data["vid1"], etc. directly (no Keys.Contains
+/// guards on required fields). Wrapping the payload under a "replay_info" key would crash the
+/// client. The controller returns the raw JsonElement directly via Ok(element).
+///
+/// C1 decision: Option (b) is superseded — client CAN handle a full payload; the bug was the
+/// wrapper key. The flat pass-through here is Option (a) variant: emit stored fields at data level.
+/// If GetReplayDetailAsync returns null (no stored replay), the controller emits result_code=2
+/// to gate the client off unguarded parsing.
 /// </summary>
-[MessagePackObject]
+// NOTE: This DTO is unused at runtime — the controller returns ActionResult directly. It is kept
+// as documentation of the wire contract and for future typed deserialization tests.
 public class GuildChatReplayDetailResponse
 {
-    /// <summary>
+    // Fields are emitted flat at the data level, not under a wrapper key.
-    /// Opaque replay payload forwarded verbatim from the stored ReplayPayload JSON.
+    // See ReplayDetailInfo.cs in the decompiled client for the full field list.
-    /// TODO(post-merge): type this properly once replay subsystem shape is captured.
+    // Key representative required fields (unguarded access in constructor):
-    /// </summary>
+    //   battleId, seed, fieldId, firstTurn, card_master_id,
-    [JsonPropertyName("replay_info"), Key("replay_info")]
+    //   vid1/name1/charaId1/classId1/emblemId1/degreeId1/countryCode1/sleeveId1/battlePoint1/masterPoint1/rank1/isOfficial1/deck1
-    public JsonElement? ReplayInfo { get; set; }
+    //   vid2/name2/charaId2/classId2/emblemId2/degreeId2/countryCode2/sleeveId2/battlePoint2/masterPoint2/rank2/isOfficial2/deck2
+
+    [JsonPropertyName("result_code")]
+    public int ResultCode { get; set; } = 1;
 }

SVSim.UnitTests/Wire/GuildWireShape.cs

@@ -211,6 +211,40 @@ public class GuildWireShape
             "root must not be an object — no 'friends' wrapper allowed");
     }
 
+    [Test]
+    public void ReplayDetail_response_passes_payload_fields_flat_not_wrapped()
+    {
+        // ChatReplayDetailTask.Parse() calls new ReplayDetailInfo(base.ResponseData["data"]).
+        // ReplayDetailInfo constructor accesses data["battleId"].ToLong(), data["seed"].ToInt(), etc.
+        // WITHOUT Keys.Contains guards. Wrapping under a "replay_info" key would crash the client.
+        // The controller emits the stored JSON element directly as the data payload — verify that
+        // the serialized shape does NOT have a wrapper key.
+        //
+        // Decompile evidence (ReplayDetailInfo.cs line 209-210):
+        //   battle_id = data["battleId"].ToLong();   // unguarded
+        //   seed = data["seed"].ToInt();             // unguarded
+        // Therefore: option (b) gate-off when payload is null; flat pass-through when it exists.
+
+        // Simulate what the controller does: serialize the payload element directly.
+        const string storedPayloadJson = """{"battleId":"999","seed":42,"fieldId":1,"firstTurn":1,"card_master_id":100,"vid1":1,"name1":"A","charaId1":1,"classId1":1,"emblemId1":100000000,"degreeId1":0,"countryCode1":"JP","sleeveId1":3000011,"battlePoint1":0,"masterPoint1":0,"rank1":1,"isOfficial1":false,"deck1":[],"vid2":2,"name2":"B","charaId2":1,"classId2":2,"emblemId2":100000000,"degreeId2":0,"countryCode2":"JP","sleeveId2":3000011,"battlePoint2":0,"masterPoint2":0,"rank2":1,"isOfficial2":false,"deck2":[]}""";
+        using var doc = JsonDocument.Parse(storedPayloadJson);
+        var element = doc.RootElement.Clone();
+
+        // Re-serialize as if returned from Ok(element) — should be flat
+        var json = JsonSerializer.Serialize(element, Opts);
+        using var resultDoc = JsonDocument.Parse(json);
+        var root = resultDoc.RootElement;
+
+        // battleId must be at root level, NOT under a "replay_info" wrapper
+        Assert.That(root.TryGetProperty("battleId", out var battleId), Is.True,
+            "battleId must be at root level — no replay_info wrapper");
+        Assert.That(battleId.GetString(), Is.EqualTo("999"));
+
+        // replay_info key must NOT exist
+        Assert.That(root.TryGetProperty("replay_info", out _), Is.False,
+            "replay_info wrapper must NOT be present — client reads data[\"battleId\"] directly");
+    }
+
     [Test]
     public void GuildInfo_non_joined_serializes_to_prod_shape()
     {