feat(guild): add Guild aggregate schema + migration

SVSim.Database/Entities/Guild/Guild.cs

@@ -0,0 +1,17 @@
+using SVSim.Database.Models;
+
+namespace SVSim.Database.Entities.Guild;
+
+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 EmblemId { get; set; }
+    public GuildActivity Activity { get; set; }
+    public GuildJoinCondition JoinCondition { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime? BreakupAt { get; set; }            // soft-delete on breakup
+    public List<GuildMember> Members { get; set; } = new();
+}

SVSim.Database/Entities/Guild/GuildChatMessage.cs

@@ -0,0 +1,16 @@
+namespace SVSim.Database.Entities.Guild;
+
+public class GuildChatMessage
+{
+    public long Id { get; set; }                    // global PK
+    public int GuildId { get; set; }
+    public int MessageId { get; set; }              // per-guild monotonic, unique with GuildId
+    public long AuthorViewerId { get; set; }
+    public GuildChatMessageType MessageType { get; set; }
+    public string Body { get; set; } = "";
+    public string? DeckPayload { get; set; }        // jsonb
+    public string? ReplayPayload { get; set; }      // jsonb
+    public string? RoomPayload { get; set; }        // jsonb
+    public DateTime CreatedAt { get; set; }
+    public Guild Guild { get; set; } = null!;
+}

SVSim.Database/Entities/Guild/GuildEnums.cs

@@ -0,0 +1,36 @@
+namespace SVSim.Database.Entities.Guild;
+
+public enum GuildRole : int
+{
+    Regular = 0,
+    Leader = 1,
+    SubLeader = 2,
+}
+
+public enum GuildJoinCondition : int
+{
+    Free = 1,
+    Approval = 2,
+    OnlyInvite = 3,
+}
+
+// Matches GuildDetailInfo.ActivityType (1..16). All / Beginner / Enjoy / Stoic / FriendOnly /
+// per-class (Elf..Nemesis) / Rotation / Unlimited / TwoPick.
+public enum GuildActivity : int
+{
+    All = 1, Beginner = 2, Enjoy = 3, Stoic = 4, FriendOnly = 5,
+    Elf = 6, Royal = 7, Witch = 8, Dragon = 9, Necro = 10,
+    Vampire = 11, Bishop = 12, Nemesis = 13,
+    Rotation = 14, Unlimited = 15, TwoPick = 16,
+}
+
+public enum GuildInviteStatus : int { Pending = 0, Canceled = 1, Rejected = 2, Consumed = 3 }
+public enum GuildJoinRequestStatus : int { Pending = 0, Canceled = 1, Rejected = 2, Accepted = 3 }
+
+// Per docs/api-spec/.../guild_chat-messages.md. 12..18 are gathering-only — never emit on guild.
+public enum GuildChatMessageType : int
+{
+    Normal = 0, Stamp = 1, Deck = 2, Join = 3, Leave = 4, Replay = 5,
+    ChangeLeader = 6, ChangeSubLeader = 7, CreateGuild = 8, Remove = 9,
+    RoomMatch = 10, Description = 11,
+}

SVSim.Database/Entities/Guild/GuildInvite.cs

@@ -0,0 +1,12 @@
+namespace SVSim.Database.Entities.Guild;
+
+public class GuildInvite
+{
+    public int GuildId { get; set; }
+    public long InviteeViewerId { get; set; }
+    public long InviterViewerId { get; set; }
+    public GuildInviteStatus Status { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime? RespondedAt { get; set; }
+    public Guild Guild { get; set; } = null!;
+}

SVSim.Database/Entities/Guild/GuildJoinRequest.cs

@@ -0,0 +1,11 @@
+namespace SVSim.Database.Entities.Guild;
+
+public class GuildJoinRequest
+{
+    public int GuildId { get; set; }
+    public long ViewerId { get; set; }
+    public GuildJoinRequestStatus Status { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime? RespondedAt { get; set; }
+    public Guild Guild { get; set; } = null!;
+}

SVSim.Database/Entities/Guild/GuildMember.cs

@@ -0,0 +1,10 @@
+namespace SVSim.Database.Entities.Guild;
+
+public class GuildMember
+{
+    public int GuildId { get; set; }
+    public long ViewerId { get; set; }
+    public GuildRole Role { get; set; }
+    public DateTime JoinedAt { get; set; }
+    public Guild Guild { get; set; } = null!;
+}

SVSim.Database/Migrations/20260627150146_AddGuildSchema.cs

@@ -0,0 +1,207 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace SVSim.Database.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddGuildSchema : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "GuildId",
+                table: "Viewers",
+                type: "integer",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "Guilds",
+                columns: table => new
+                {
+                    GuildId = table.Column<int>(type: "integer", nullable: false),
+                    Name = table.Column<string>(type: "character varying(64)", maxLength: 64, nullable: false),
+                    Description = table.Column<string>(type: "character varying(512)", maxLength: 512, nullable: false),
+                    LeaderViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    EmblemId = table.Column<long>(type: "bigint", nullable: false),
+                    Activity = table.Column<int>(type: "integer", nullable: false),
+                    JoinCondition = table.Column<int>(type: "integer", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    BreakupAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Guilds", x => x.GuildId);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "GuildChatMessages",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    GuildId = table.Column<int>(type: "integer", nullable: false),
+                    MessageId = table.Column<int>(type: "integer", nullable: false),
+                    AuthorViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    MessageType = table.Column<int>(type: "integer", nullable: false),
+                    Body = table.Column<string>(type: "text", nullable: false),
+                    DeckPayload = table.Column<string>(type: "jsonb", nullable: true),
+                    ReplayPayload = table.Column<string>(type: "jsonb", nullable: true),
+                    RoomPayload = table.Column<string>(type: "jsonb", nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_GuildChatMessages", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_GuildChatMessages_Guilds_GuildId",
+                        column: x => x.GuildId,
+                        principalTable: "Guilds",
+                        principalColumn: "GuildId",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "GuildInvites",
+                columns: table => new
+                {
+                    GuildId = table.Column<int>(type: "integer", nullable: false),
+                    InviteeViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    InviterViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    Status = table.Column<int>(type: "integer", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    RespondedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_GuildInvites", x => new { x.GuildId, x.InviteeViewerId });
+                    table.ForeignKey(
+                        name: "FK_GuildInvites_Guilds_GuildId",
+                        column: x => x.GuildId,
+                        principalTable: "Guilds",
+                        principalColumn: "GuildId",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "GuildJoinRequests",
+                columns: table => new
+                {
+                    GuildId = table.Column<int>(type: "integer", nullable: false),
+                    ViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    Status = table.Column<int>(type: "integer", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    RespondedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_GuildJoinRequests", x => new { x.GuildId, x.ViewerId });
+                    table.ForeignKey(
+                        name: "FK_GuildJoinRequests_Guilds_GuildId",
+                        column: x => x.GuildId,
+                        principalTable: "Guilds",
+                        principalColumn: "GuildId",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "GuildMembers",
+                columns: table => new
+                {
+                    GuildId = table.Column<int>(type: "integer", nullable: false),
+                    ViewerId = table.Column<long>(type: "bigint", nullable: false),
+                    Role = table.Column<int>(type: "integer", nullable: false),
+                    JoinedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_GuildMembers", x => new { x.GuildId, x.ViewerId });
+                    table.ForeignKey(
+                        name: "FK_GuildMembers_Guilds_GuildId",
+                        column: x => x.GuildId,
+                        principalTable: "Guilds",
+                        principalColumn: "GuildId",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Viewers_GuildId",
+                table: "Viewers",
+                column: "GuildId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GuildChatMessages_GuildId_MessageId",
+                table: "GuildChatMessages",
+                columns: new[] { "GuildId", "MessageId" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GuildInvites_InviteeViewerId_Status",
+                table: "GuildInvites",
+                columns: new[] { "InviteeViewerId", "Status" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GuildJoinRequests_GuildId_Status",
+                table: "GuildJoinRequests",
+                columns: new[] { "GuildId", "Status" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GuildJoinRequests_ViewerId_Status",
+                table: "GuildJoinRequests",
+                columns: new[] { "ViewerId", "Status" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GuildMembers_ViewerId",
+                table: "GuildMembers",
+                column: "ViewerId",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Guilds_Name",
+                table: "Guilds",
+                column: "Name");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Viewers_Guilds_GuildId",
+                table: "Viewers",
+                column: "GuildId",
+                principalTable: "Guilds",
+                principalColumn: "GuildId",
+                onDelete: ReferentialAction.SetNull);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Viewers_Guilds_GuildId",
+                table: "Viewers");
+
+            migrationBuilder.DropTable(
+                name: "GuildChatMessages");
+
+            migrationBuilder.DropTable(
+                name: "GuildInvites");
+
+            migrationBuilder.DropTable(
+                name: "GuildJoinRequests");
+
+            migrationBuilder.DropTable(
+                name: "GuildMembers");
+
+            migrationBuilder.DropTable(
+                name: "Guilds");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Viewers_GuildId",
+                table: "Viewers");
+
+            migrationBuilder.DropColumn(
+                name: "GuildId",
+                table: "Viewers");
+        }
+    }
+}

SVSim.Database/Migrations/SVSimDbContextModelSnapshot.cs

@@ -85,6 +85,165 @@ namespace SVSim.Database.Migrations
                     b.ToTable("MyPageBackgroundEntryViewer");
                 });
 
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.Guild", b =>
+                {
+                    b.Property<int>("GuildId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("Activity")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime?>("BreakupAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)");
+
+                    b.Property<long>("EmblemId")
+                        .HasColumnType("bigint");
+
+                    b.Property<int>("JoinCondition")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("LeaderViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.HasKey("GuildId");
+
+                    b.HasIndex("Name");
+
+                    b.ToTable("Guilds");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildChatMessage", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("AuthorViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("Body")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("DeckPayload")
+                        .HasColumnType("jsonb");
+
+                    b.Property<int>("GuildId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("MessageId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("MessageType")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ReplayPayload")
+                        .HasColumnType("jsonb");
+
+                    b.Property<string>("RoomPayload")
+                        .HasColumnType("jsonb");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("GuildId", "MessageId")
+                        .IsUnique();
+
+                    b.ToTable("GuildChatMessages");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildInvite", b =>
+                {
+                    b.Property<int>("GuildId")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("InviteeViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long>("InviterViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime?>("RespondedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.HasKey("GuildId", "InviteeViewerId");
+
+                    b.HasIndex("InviteeViewerId", "Status");
+
+                    b.ToTable("GuildInvites");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildJoinRequest", b =>
+                {
+                    b.Property<int>("GuildId")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("ViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTime?>("RespondedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.HasKey("GuildId", "ViewerId");
+
+                    b.HasIndex("GuildId", "Status");
+
+                    b.HasIndex("ViewerId", "Status");
+
+                    b.ToTable("GuildJoinRequests");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildMember", b =>
+                {
+                    b.Property<int>("GuildId")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("ViewerId")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTime>("JoinedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Role")
+                        .HasColumnType("integer");
+
+                    b.HasKey("GuildId", "ViewerId");
+
+                    b.HasIndex("ViewerId")
+                        .IsUnique();
+
+                    b.ToTable("GuildMembers");
+                });
+
             modelBuilder.Entity("SVSim.Database.Entities.Story.SpecialBattleSetting", b =>
                 {
                     b.Property<int>("Id")
@@ -2685,6 +2844,9 @@ namespace SVSim.Database.Migrations
                         .IsRequired()
                         .HasColumnType("text");
 
+                    b.Property<int?>("GuildId")
+                        .HasColumnType("integer");
+
                     b.Property<DateTime>("LastLogin")
                         .HasColumnType("timestamp with time zone");
 
@@ -2712,6 +2874,8 @@ namespace SVSim.Database.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("GuildId");
+
                     b.HasIndex("ShortUdid");
 
                     b.HasIndex("Udid")
@@ -3479,6 +3643,50 @@ namespace SVSim.Database.Migrations
                         .IsRequired();
                 });
 
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildChatMessage", b =>
+                {
+                    b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")
+                        .WithMany()
+                        .HasForeignKey("GuildId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Guild");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildInvite", b =>
+                {
+                    b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")
+                        .WithMany()
+                        .HasForeignKey("GuildId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Guild");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildJoinRequest", b =>
+                {
+                    b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")
+                        .WithMany()
+                        .HasForeignKey("GuildId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Guild");
+                });
+
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.GuildMember", b =>
+                {
+                    b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")
+                        .WithMany("Members")
+                        .HasForeignKey("GuildId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Guild");
+                });
+
             modelBuilder.Entity("SVSim.Database.Entities.Story.StoryChapter", b =>
                 {
                     b.HasOne("SVSim.Database.Entities.Story.StorySection", "Section")
@@ -4112,6 +4320,11 @@ namespace SVSim.Database.Migrations
 
             modelBuilder.Entity("SVSim.Database.Models.Viewer", b =>
                 {
+                    b.HasOne("SVSim.Database.Entities.Guild.Guild", "Guild")
+                        .WithMany()
+                        .HasForeignKey("GuildId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
                     b.OwnsMany("SVSim.Database.Models.MyPageBgRotationEntry", "MyPageBgRotation", b1 =>
                         {
                             b1.Property<long>("ViewerId")
@@ -4588,6 +4801,8 @@ namespace SVSim.Database.Migrations
 
                     b.Navigation("GachaPointReceived");
 
+                    b.Navigation("Guild");
+
                     b.Navigation("Info")
                         .IsRequired();
 
@@ -4719,6 +4934,11 @@ namespace SVSim.Database.Migrations
                         .IsRequired();
                 });
 
+            modelBuilder.Entity("SVSim.Database.Entities.Guild.Guild", b =>
+                {
+                    b.Navigation("Members");
+                });
+
             modelBuilder.Entity("SVSim.Database.Models.BattlePassSeasonEntry", b =>
                 {
                     b.Navigation("Rewards");

SVSim.Database/Models/Viewer.cs

@@ -105,5 +105,8 @@ public class Viewer : BaseEntity<long>
 
     public List<SocialAccountConnection> SocialAccountConnections { get; set; } = new List<SocialAccountConnection>();
 
+    public int? GuildId { get; set; }
+    public SVSim.Database.Entities.Guild.Guild? Guild { get; set; }
+
     #endregion
 }

SVSim.Database/SVSimDbContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using SVSim.Database.Common;
+using SVSim.Database.Entities.Guild;
 using SVSim.Database.Entities.Story;
 using SVSim.Database.Models;
 using SVSim.Database.Models.Config;
@@ -119,6 +120,12 @@ public class SVSimDbContext : DbContext
     public DbSet<ViewerPlayedTogether> ViewerPlayedTogethers => Set<ViewerPlayedTogether>();
     public DbSet<ViewerBattleHistory> ViewerBattleHistories => Set<ViewerBattleHistory>();
 
+    public DbSet<Guild> Guilds => Set<Guild>();
+    public DbSet<GuildMember> GuildMembers => Set<GuildMember>();
+    public DbSet<GuildInvite> GuildInvites => Set<GuildInvite>();
+    public DbSet<GuildJoinRequest> GuildJoinRequests => Set<GuildJoinRequest>();
+    public DbSet<GuildChatMessage> GuildChatMessages => Set<GuildChatMessage>();
+
     #endregion
 
     public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
@@ -504,6 +511,59 @@ public class SVSimDbContext : DbContext
         modelBuilder.Entity<ColosseumWindFallDeck>().HasIndex(d => d.DeckNo).IsUnique();
         modelBuilder.Entity<ColosseumAvatarDeck>().HasIndex(d => d.DeckNo).IsUnique();
 
+        // --- Guild entities ---
+
+        modelBuilder.Entity<Guild>(e =>
+        {
+            e.HasKey(g => g.GuildId);
+            e.Property(g => g.GuildId).ValueGeneratedNever();     // we pick the random id ourselves
+            e.Property(g => g.Name).HasMaxLength(64);
+            e.Property(g => g.Description).HasMaxLength(512);
+            e.HasIndex(g => g.Name);                              // name search
+        });
+
+        modelBuilder.Entity<GuildMember>(e =>
+        {
+            e.HasKey(m => new { m.GuildId, m.ViewerId });
+            e.HasOne(m => m.Guild).WithMany(g => g.Members).HasForeignKey(m => m.GuildId)
+                .OnDelete(DeleteBehavior.Cascade);
+            e.HasIndex(m => m.ViewerId).IsUnique();               // one-guild-per-viewer at DB level
+        });
+
+        modelBuilder.Entity<GuildInvite>(e =>
+        {
+            e.HasKey(i => new { i.GuildId, i.InviteeViewerId });
+            e.HasOne(i => i.Guild).WithMany().HasForeignKey(i => i.GuildId)
+                .OnDelete(DeleteBehavior.Cascade);
+            e.HasIndex(i => new { i.InviteeViewerId, i.Status }); // "my pending invites"
+        });
+
+        modelBuilder.Entity<GuildJoinRequest>(e =>
+        {
+            e.HasKey(r => new { r.GuildId, r.ViewerId });
+            e.HasOne(r => r.Guild).WithMany().HasForeignKey(r => r.GuildId)
+                .OnDelete(DeleteBehavior.Cascade);
+            e.HasIndex(r => new { r.ViewerId, r.Status });
+            e.HasIndex(r => new { r.GuildId, r.Status });
+        });
+
+        modelBuilder.Entity<GuildChatMessage>(e =>
+        {
+            e.HasKey(c => c.Id);
+            e.HasOne(c => c.Guild).WithMany().HasForeignKey(c => c.GuildId)
+                .OnDelete(DeleteBehavior.Cascade);
+            e.HasIndex(c => new { c.GuildId, c.MessageId }).IsUnique();
+            e.Property(c => c.DeckPayload).HasColumnType("jsonb");
+            e.Property(c => c.ReplayPayload).HasColumnType("jsonb");
+            e.Property(c => c.RoomPayload).HasColumnType("jsonb");
+        });
+
+        modelBuilder.Entity<Viewer>(e =>
+        {
+            e.HasOne(v => v.Guild).WithMany().HasForeignKey(v => v.GuildId)
+                .OnDelete(DeleteBehavior.SetNull);
+        });
+
         base.OnModelCreating(modelBuilder);
     }