Phase 9 Wave 1: add ReleaseMedium discriminator + Session/Mix metadata

Add ReleaseMedium enum (Cut/Session/Mix) and two 1:1 satellite entities
(SessionMetadata, MixMetadata) with EF configs and an additive migration.
ReleaseDto.ReleaseType is now nullable, nulled for non-Cut at the converter.
Existing releases default to Cut via column default; no data migration.

DeepDrftData/Data/Configurations/MixMetadataConfiguration.cs

@@ -0,0 +1,48 @@
+using Data.Data.Configurations;
+using DeepDrftModels.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace DeepDrftData.Data.Configurations;
+
+public class MixMetadataConfiguration : BaseEntityConfiguration<MixMetadata>
+{
+    public override void Configure(EntityTypeBuilder<MixMetadata> builder)
+    {
+        // Wires up Id PK + audit columns (CreatedAt, UpdatedAt, IsDeleted) and the IsDeleted index.
+        base.Configure(builder);
+
+        builder.ToTable("mix_metadata");
+
+        // Map the base audit columns to the snake_case naming the rest of the schema uses.
+        builder.Property(e => e.Id).HasColumnName("id");
+        builder.Property(e => e.CreatedAt).HasColumnName("created_at");
+        builder.Property(e => e.UpdatedAt).HasColumnName("updated_at");
+        builder.Property(e => e.IsDeleted).HasColumnName("is_deleted");
+
+        builder.Property(e => e.ReleaseId)
+            .HasColumnName("release_id");
+
+        builder.Property(e => e.WaveformEntryKey)
+            .IsRequired()
+            .HasMaxLength(500)   // Consistent with ImagePath on ReleaseEntity; entry keys can carry GUIDs.
+            .HasColumnName("waveform_entry_key");
+
+        // 1:1 to the parent release. The unique FK index is the DB-level enforcement of the
+        // one-satellite-per-release cardinality. Cascade on delete: removing the release removes its
+        // medium satellite (unlike Track's SetNull — a satellite has no meaning without its release).
+        builder.HasOne(e => e.Release)
+            .WithOne(r => r.MixMetadata)
+            .HasForeignKey<MixMetadata>(e => e.ReleaseId)
+            .OnDelete(DeleteBehavior.Cascade);
+
+        builder.HasIndex(e => e.ReleaseId)
+            .IsUnique()
+            .HasDatabaseName("IX_mix_metadata_release_id");
+
+        // Names the is_deleted index explicitly. BaseEntityConfiguration.Configure already
+        // calls HasIndex(e => e.IsDeleted); this adds HasDatabaseName so EF always uses
+        // "IX_mix_metadata_is_deleted" regardless of auto-naming conventions.
+        builder.HasIndex(e => e.IsDeleted).HasDatabaseName("IX_mix_metadata_is_deleted");
+    }
+}

DeepDrftData/Data/Configurations/ReleaseConfiguration.cs

@@ -42,6 +42,18 @@ public class ReleaseConfiguration : BaseEntityConfiguration<ReleaseEntity>
             .HasMaxLength(500)
             .HasColumnName("image_path");
 
+        // ReleaseType is meaningful ONLY when Medium == Cut. It is the Cut medium's discriminator
+        // data and lives on the base table by deliberate, named exception:
+        //   A CutMetadata satellite (mirroring SessionMetadata/MixMetadata) was considered and
+        //   rejected. ReleaseType is read on every card of the /cuts browse — the highest-traffic
+        //   read in the system. Moving it to a satellite would put a join on that hot path. So it
+        //   stays here. Future media MUST NOT copy this pattern: the default is a satellite metadata
+        //   table; this is the one allowed exception, justified solely by the /cuts read volume.
+        //
+        // The "ReleaseType only for Cut" invariant is advisory — enforced at the service layer and
+        // surfaced via the nullable ReleaseDto.ReleaseType (nulled for non-Cut at the converter).
+        // It is NOT a DB check constraint by choice, not necessity: EF supports HasCheckConstraint,
+        // but the invariant is advisory and we keep the schema free of it.
         builder.Property(e => e.ReleaseType)
             .IsRequired()
             .HasConversion<string>()   // Store as readable string, not int ordinal
@@ -49,6 +61,13 @@ public class ReleaseConfiguration : BaseEntityConfiguration<ReleaseEntity>
             .HasColumnName("release_type")
             .HasDefaultValue(ReleaseType.Single);
 
+        builder.Property(e => e.Medium)
+            .IsRequired()
+            .HasConversion<string>()   // Store as readable string, not int ordinal
+            .HasMaxLength(20)
+            .HasColumnName("medium")
+            .HasDefaultValue(ReleaseMedium.Cut);   // Existing rows migrate to Cut with no data migration.
+
         builder.Property(e => e.CreatedByUserId)
             .HasColumnName("created_by_user_id");
 

DeepDrftData/Data/Configurations/SessionMetadataConfiguration.cs

@@ -0,0 +1,48 @@
+using Data.Data.Configurations;
+using DeepDrftModels.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace DeepDrftData.Data.Configurations;
+
+public class SessionMetadataConfiguration : BaseEntityConfiguration<SessionMetadata>
+{
+    public override void Configure(EntityTypeBuilder<SessionMetadata> builder)
+    {
+        // Wires up Id PK + audit columns (CreatedAt, UpdatedAt, IsDeleted) and the IsDeleted index.
+        base.Configure(builder);
+
+        builder.ToTable("session_metadata");
+
+        // Map the base audit columns to the snake_case naming the rest of the schema uses.
+        builder.Property(e => e.Id).HasColumnName("id");
+        builder.Property(e => e.CreatedAt).HasColumnName("created_at");
+        builder.Property(e => e.UpdatedAt).HasColumnName("updated_at");
+        builder.Property(e => e.IsDeleted).HasColumnName("is_deleted");
+
+        builder.Property(e => e.ReleaseId)
+            .HasColumnName("release_id");
+
+        builder.Property(e => e.HeroImageEntryKey)
+            .IsRequired()
+            .HasMaxLength(500)   // Consistent with ImagePath on ReleaseEntity; entry keys can carry GUIDs.
+            .HasColumnName("hero_image_entry_key");
+
+        // 1:1 to the parent release. The unique FK index is the DB-level enforcement of the
+        // one-satellite-per-release cardinality. Cascade on delete: removing the release removes its
+        // medium satellite (unlike Track's SetNull — a satellite has no meaning without its release).
+        builder.HasOne(e => e.Release)
+            .WithOne(r => r.SessionMetadata)
+            .HasForeignKey<SessionMetadata>(e => e.ReleaseId)
+            .OnDelete(DeleteBehavior.Cascade);
+
+        builder.HasIndex(e => e.ReleaseId)
+            .IsUnique()
+            .HasDatabaseName("IX_session_metadata_release_id");
+
+        // Names the is_deleted index explicitly. BaseEntityConfiguration.Configure already
+        // calls HasIndex(e => e.IsDeleted); this adds HasDatabaseName so EF always uses
+        // "IX_session_metadata_is_deleted" regardless of auto-naming conventions.
+        builder.HasIndex(e => e.IsDeleted).HasDatabaseName("IX_session_metadata_is_deleted");
+    }
+}

DeepDrftData/Data/DeepDrftContext.cs

@@ -12,6 +12,8 @@ public class DeepDrftContext : DbContext
 
     public DbSet<TrackEntity> Tracks { get; set; }
     public DbSet<ReleaseEntity> Releases { get; set; }
+    public DbSet<SessionMetadata> SessionMetadata { get; set; }
+    public DbSet<MixMetadata> MixMetadata { get; set; }
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
@@ -19,5 +21,7 @@ public class DeepDrftContext : DbContext
 
         modelBuilder.ApplyConfiguration(new TrackConfiguration());
         modelBuilder.ApplyConfiguration(new ReleaseConfiguration());
+        modelBuilder.ApplyConfiguration(new SessionMetadataConfiguration());
+        modelBuilder.ApplyConfiguration(new MixMetadataConfiguration());
     }
 }

DeepDrftData/Migrations/20260613013826_AddReleaseMedium.Designer.cs

@@ -0,0 +1,303 @@
+// <auto-generated />
+using System;
+using DeepDrftData.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace DeepDrftData.Migrations
+{
+    [DbContext(typeof(DeepDrftContext))]
+    [Migration("20260613013826_AddReleaseMedium")]
+    partial class AddReleaseMedium
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.7")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("DeepDrftModels.Entities.MixMetadata", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<long>("ReleaseId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("release_id");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.Property<string>("WaveformEntryKey")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("waveform_entry_key");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_mix_metadata_is_deleted");
+
+                    b.HasIndex("ReleaseId")
+                        .IsUnique()
+                        .HasDatabaseName("IX_mix_metadata_release_id");
+
+                    b.ToTable("mix_metadata", (string)null);
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.ReleaseEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Artist")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)")
+                        .HasColumnName("artist");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<long?>("CreatedByUserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("created_by_user_id");
+
+                    b.Property<string>("Genre")
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)")
+                        .HasColumnName("genre");
+
+                    b.Property<string>("ImagePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("image_path");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<string>("Medium")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasDefaultValue("Cut")
+                        .HasColumnName("medium");
+
+                    b.Property<DateOnly?>("ReleaseDate")
+                        .HasColumnType("date")
+                        .HasColumnName("release_date");
+
+                    b.Property<string>("ReleaseType")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasDefaultValue("Single")
+                        .HasColumnName("release_type");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)")
+                        .HasColumnName("title");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_release_is_deleted");
+
+                    b.HasIndex("Title", "Artist")
+                        .IsUnique()
+                        .HasDatabaseName("IX_release_title_artist")
+                        .HasFilter("\"is_deleted\" = false");
+
+                    b.ToTable("release", (string)null);
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.SessionMetadata", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<string>("HeroImageEntryKey")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("hero_image_entry_key");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<long>("ReleaseId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("release_id");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_session_metadata_is_deleted");
+
+                    b.HasIndex("ReleaseId")
+                        .IsUnique()
+                        .HasDatabaseName("IX_session_metadata_release_id");
+
+                    b.ToTable("session_metadata", (string)null);
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.TrackEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<string>("EntryKey")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)")
+                        .HasColumnName("entry_key");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<string>("OriginalFileName")
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("original_file_name");
+
+                    b.Property<long?>("ReleaseId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("release_id");
+
+                    b.Property<string>("TrackName")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)")
+                        .HasColumnName("track_name");
+
+                    b.Property<int>("TrackNumber")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(1)
+                        .HasColumnName("track_number");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_track_is_deleted");
+
+                    b.HasIndex("ReleaseId");
+
+                    b.ToTable("track", (string)null);
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.MixMetadata", b =>
+                {
+                    b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
+                        .WithOne("MixMetadata")
+                        .HasForeignKey("DeepDrftModels.Entities.MixMetadata", "ReleaseId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Release");
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.SessionMetadata", b =>
+                {
+                    b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
+                        .WithOne("SessionMetadata")
+                        .HasForeignKey("DeepDrftModels.Entities.SessionMetadata", "ReleaseId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Release");
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.TrackEntity", b =>
+                {
+                    b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
+                        .WithMany("Tracks")
+                        .HasForeignKey("ReleaseId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Release");
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.ReleaseEntity", b =>
+                {
+                    b.Navigation("MixMetadata");
+
+                    b.Navigation("SessionMetadata");
+
+                    b.Navigation("Tracks");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

DeepDrftData/Migrations/20260613013826_AddReleaseMedium.cs

@@ -0,0 +1,106 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace DeepDrftData.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddReleaseMedium : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "medium",
+                table: "release",
+                type: "character varying(20)",
+                maxLength: 20,
+                nullable: false,
+                defaultValue: "Cut");
+
+            migrationBuilder.CreateTable(
+                name: "mix_metadata",
+                columns: table => new
+                {
+                    id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    release_id = table.Column<long>(type: "bigint", nullable: false),
+                    waveform_entry_key = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: false),
+                    created_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    updated_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    is_deleted = table.Column<bool>(type: "boolean", nullable: false, defaultValue: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_mix_metadata", x => x.id);
+                    table.ForeignKey(
+                        name: "FK_mix_metadata_release_release_id",
+                        column: x => x.release_id,
+                        principalTable: "release",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "session_metadata",
+                columns: table => new
+                {
+                    id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    release_id = table.Column<long>(type: "bigint", nullable: false),
+                    hero_image_entry_key = table.Column<string>(type: "character varying(500)", maxLength: 500, nullable: false),
+                    created_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    updated_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    is_deleted = table.Column<bool>(type: "boolean", nullable: false, defaultValue: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_session_metadata", x => x.id);
+                    table.ForeignKey(
+                        name: "FK_session_metadata_release_release_id",
+                        column: x => x.release_id,
+                        principalTable: "release",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_mix_metadata_is_deleted",
+                table: "mix_metadata",
+                column: "is_deleted");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_mix_metadata_release_id",
+                table: "mix_metadata",
+                column: "release_id",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_session_metadata_is_deleted",
+                table: "session_metadata",
+                column: "is_deleted");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_session_metadata_release_id",
+                table: "session_metadata",
+                column: "release_id",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "mix_metadata");
+
+            migrationBuilder.DropTable(
+                name: "session_metadata");
+
+            migrationBuilder.DropColumn(
+                name: "medium",
+                table: "release");
+        }
+    }
+}

DeepDrftData/Migrations/DeepDrftContextModelSnapshot.cs

@@ -22,6 +22,51 @@ namespace DeepDrftData.Migrations
 
             NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
 
+            modelBuilder.Entity("DeepDrftModels.Entities.MixMetadata", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<long>("ReleaseId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("release_id");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.Property<string>("WaveformEntryKey")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("waveform_entry_key");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_mix_metadata_is_deleted");
+
+                    b.HasIndex("ReleaseId")
+                        .IsUnique()
+                        .HasDatabaseName("IX_mix_metadata_release_id");
+
+                    b.ToTable("mix_metadata", (string)null);
+                });
+
             modelBuilder.Entity("DeepDrftModels.Entities.ReleaseEntity", b =>
                 {
                     b.Property<long>("Id")
@@ -61,6 +106,14 @@ namespace DeepDrftData.Migrations
                         .HasDefaultValue(false)
                         .HasColumnName("is_deleted");
 
+                    b.Property<string>("Medium")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(20)
+                        .HasColumnType("character varying(20)")
+                        .HasDefaultValue("Cut")
+                        .HasColumnName("medium");
+
                     b.Property<DateOnly?>("ReleaseDate")
                         .HasColumnType("date")
                         .HasColumnName("release_date");
@@ -96,6 +149,51 @@ namespace DeepDrftData.Migrations
                     b.ToTable("release", (string)null);
                 });
 
+            modelBuilder.Entity("DeepDrftModels.Entities.SessionMetadata", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at");
+
+                    b.Property<string>("HeroImageEntryKey")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("character varying(500)")
+                        .HasColumnName("hero_image_entry_key");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(false)
+                        .HasColumnName("is_deleted");
+
+                    b.Property<long>("ReleaseId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("release_id");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("IsDeleted")
+                        .HasDatabaseName("IX_session_metadata_is_deleted");
+
+                    b.HasIndex("ReleaseId")
+                        .IsUnique()
+                        .HasDatabaseName("IX_session_metadata_release_id");
+
+                    b.ToTable("session_metadata", (string)null);
+                });
+
             modelBuilder.Entity("DeepDrftModels.Entities.TrackEntity", b =>
                 {
                     b.Property<long>("Id")
@@ -156,6 +254,28 @@ namespace DeepDrftData.Migrations
                     b.ToTable("track", (string)null);
                 });
 
+            modelBuilder.Entity("DeepDrftModels.Entities.MixMetadata", b =>
+                {
+                    b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
+                        .WithOne("MixMetadata")
+                        .HasForeignKey("DeepDrftModels.Entities.MixMetadata", "ReleaseId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Release");
+                });
+
+            modelBuilder.Entity("DeepDrftModels.Entities.SessionMetadata", b =>
+                {
+                    b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
+                        .WithOne("SessionMetadata")
+                        .HasForeignKey("DeepDrftModels.Entities.SessionMetadata", "ReleaseId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Release");
+                });
+
             modelBuilder.Entity("DeepDrftModels.Entities.TrackEntity", b =>
                 {
                     b.HasOne("DeepDrftModels.Entities.ReleaseEntity", "Release")
@@ -168,6 +288,10 @@ namespace DeepDrftData.Migrations
 
             modelBuilder.Entity("DeepDrftModels.Entities.ReleaseEntity", b =>
                 {
+                    b.Navigation("MixMetadata");
+
+                    b.Navigation("SessionMetadata");
+
                     b.Navigation("Tracks");
                 });
 #pragma warning restore 612, 618

DeepDrftData/TrackConverter.cs

@@ -1,5 +1,6 @@
 using DeepDrftModels.DTOs;
 using DeepDrftModels.Entities;
+using DeepDrftModels.Enums;
 using Models.Converters;
 
 namespace DeepDrftData;
@@ -25,7 +26,24 @@ public class TrackConverter : IEntityToModelConverter<TrackEntity, TrackDto>
         Genre = entity.Genre,
         ReleaseDate = entity.ReleaseDate,
         ImagePath = entity.ImagePath,
-        ReleaseType = entity.ReleaseType,
+        Medium = entity.Medium,
+        // ReleaseType is meaningful only for Cut; null it for Session/Mix at the mapping point so no
+        // consumer mistakes a stale studio-format value for a live/mix release.
+        ReleaseType = entity.Medium == ReleaseMedium.Cut ? entity.ReleaseType : (ReleaseType?)null,
+        SessionMetadata = entity.SessionMetadata is null
+            ? null
+            : new SessionMetadataDto
+            {
+                ReleaseId = entity.SessionMetadata.ReleaseId,
+                HeroImageEntryKey = entity.SessionMetadata.HeroImageEntryKey
+            },
+        MixMetadata = entity.MixMetadata is null
+            ? null
+            : new MixMetadataDto
+            {
+                ReleaseId = entity.MixMetadata.ReleaseId,
+                WaveformEntryKey = entity.MixMetadata.WaveformEntryKey
+            },
         CreatedByUserId = entity.CreatedByUserId
     };
 
@@ -39,7 +57,10 @@ public class TrackConverter : IEntityToModelConverter<TrackEntity, TrackDto>
         Genre = dto.Genre,
         ReleaseDate = dto.ReleaseDate,
         ImagePath = dto.ImagePath,
-        ReleaseType = dto.ReleaseType,
+        Medium = dto.Medium,
+        // Entity ReleaseType is non-nullable; default back to Single when the DTO nulled it for a
+        // non-Cut release. Primarily a write-path reconstruction concern.
+        ReleaseType = dto.ReleaseType ?? ReleaseType.Single,
         CreatedByUserId = dto.CreatedByUserId
     };
 

DeepDrftData/TrackManager.cs

@@ -3,6 +3,7 @@ using Data.Managers;
 using DeepDrftData.Repositories;
 using DeepDrftModels.DTOs;
 using DeepDrftModels.Entities;
+using DeepDrftModels.Enums;
 using Microsoft.Extensions.Logging;
 using Models.Common;
 using NetBlocks.Models;
@@ -263,7 +264,10 @@ public class TrackManager
                     releaseEntity.Genre = release.Genre;
                     releaseEntity.ReleaseDate = release.ReleaseDate;
                     releaseEntity.ImagePath = release.ImagePath;
-                    releaseEntity.ReleaseType = release.ReleaseType;
+                    releaseEntity.Medium = release.Medium;
+                    // DTO ReleaseType is nullable (meaningful only for Cut); the entity field is not.
+                    // Default to Single when null, matching TrackConverter.Convert(ReleaseDto).
+                    releaseEntity.ReleaseType = release.ReleaseType ?? ReleaseType.Single;
                     releaseEntity.CreatedByUserId = release.CreatedByUserId;
                     await Repository.UpdateReleaseAsync(releaseEntity);
                 }

DeepDrftModels/DTOs/MixMetadataDto.cs

@@ -0,0 +1,10 @@
+namespace DeepDrftModels.DTOs;
+
+// Mirror of MixMetadata (Phase 9). No `required` members — BlazorBlocks's Manager<> generic
+// constraint requires `new()`, which does not compose with required members. TrackConverter assigns
+// every field on the round-trip, so an empty default is never observable.
+public class MixMetadataDto
+{
+    public long ReleaseId { get; set; }
+    public string WaveformEntryKey { get; set; } = string.Empty;
+}

DeepDrftModels/DTOs/ReleaseDto.cs

@@ -14,7 +14,16 @@ public class ReleaseDto : BaseModel
     public string? Genre { get; set; }
     public DateOnly? ReleaseDate { get; set; }
     public string? ImagePath { get; set; }
-    public ReleaseType ReleaseType { get; set; } = ReleaseType.Single;
+    public ReleaseMedium Medium { get; set; } = ReleaseMedium.Cut;
+
+    // Nullable: meaningful only for Cut releases. TrackConverter nulls it for Session/Mix at the
+    // mapping point. One producer enforces the rule; no consumer depends on a non-null value.
+    public ReleaseType? ReleaseType { get; set; }
+
+    // Medium-specific satellites. Populated only for the matching medium; null otherwise.
+    public SessionMetadataDto? SessionMetadata { get; set; }
+    public MixMetadataDto? MixMetadata { get; set; }
+
     public long? CreatedByUserId { get; set; }
 
     // Read-model field: count of non-deleted tracks in this release. Not on ReleaseEntity — the

DeepDrftModels/DTOs/SessionMetadataDto.cs

@@ -0,0 +1,10 @@
+namespace DeepDrftModels.DTOs;
+
+// Mirror of SessionMetadata (Phase 9). No `required` members — BlazorBlocks's Manager<> generic
+// constraint requires `new()`, which does not compose with required members. TrackConverter assigns
+// every field on the round-trip, so an empty default is never observable.
+public class SessionMetadataDto
+{
+    public long ReleaseId { get; set; }
+    public string HeroImageEntryKey { get; set; } = string.Empty;
+}

DeepDrftModels/Entities/MixMetadata.cs

@@ -0,0 +1,17 @@
+using Models.Entities;
+
+namespace DeepDrftModels.Entities;
+
+// 1:1 satellite for Mix-medium releases (Phase 9). One row per Mix ReleaseEntity, keyed by a unique
+// ReleaseId FK (the 1:1 enforcement lives in MixMetadataConfiguration). Carries the entry key for
+// the preprocessed high-resolution waveform datum.
+//
+// Inherits Id, CreatedAt, UpdatedAt, IsDeleted from BaseEntity (Cerebellum.BlazorBlocks.Models).
+// BaseEntity ships the audit columns but does not declare IEntity itself, so subclasses declare it
+// explicitly to satisfy the generic constraints on Repository<>/Manager<>/etc.
+public class MixMetadata : BaseEntity, IEntity
+{
+    public long ReleaseId { get; set; }
+    public ReleaseEntity Release { get; set; } = null!;
+    public required string WaveformEntryKey { get; set; }
+}

DeepDrftModels/Entities/ReleaseEntity.cs

@@ -18,6 +18,13 @@ public class ReleaseEntity : BaseEntity, IEntity
     public DateOnly? ReleaseDate { get; set; }
     public string? ImagePath { get; set; }
     public ReleaseType ReleaseType { get; set; } = ReleaseType.Single;
+    public ReleaseMedium Medium { get; set; } = ReleaseMedium.Cut;
     public long? CreatedByUserId { get; set; }
     public ICollection<TrackEntity> Tracks { get; set; } = new List<TrackEntity>();
+
+    // 1:1 satellites selected by Medium. Null unless this release is the matching medium —
+    // Session releases carry SessionMetadata, Mix releases carry MixMetadata, Cut releases carry
+    // neither (ReleaseType on this table is their discriminator data).
+    public SessionMetadata? SessionMetadata { get; set; }
+    public MixMetadata? MixMetadata { get; set; }
 }

DeepDrftModels/Entities/SessionMetadata.cs

@@ -0,0 +1,17 @@
+using Models.Entities;
+
+namespace DeepDrftModels.Entities;
+
+// 1:1 satellite for Session-medium releases (Phase 9). One row per Session ReleaseEntity, keyed by
+// a unique ReleaseId FK (the 1:1 enforcement lives in SessionMetadataConfiguration). Carries the
+// hero-image entry key into the Image vault.
+//
+// Inherits Id, CreatedAt, UpdatedAt, IsDeleted from BaseEntity (Cerebellum.BlazorBlocks.Models).
+// BaseEntity ships the audit columns but does not declare IEntity itself, so subclasses declare it
+// explicitly to satisfy the generic constraints on Repository<>/Manager<>/etc.
+public class SessionMetadata : BaseEntity, IEntity
+{
+    public long ReleaseId { get; set; }
+    public ReleaseEntity Release { get; set; } = null!;
+    public required string HeroImageEntryKey { get; set; }
+}

DeepDrftModels/Enums/ReleaseMedium.cs

@@ -0,0 +1,16 @@
+namespace DeepDrftModels.Enums;
+
+/// <summary>
+/// The medium of a release — the Phase 9 discriminator that selects which metadata shape applies.
+/// </summary>
+public enum ReleaseMedium
+{
+    /// <summary>Studio recording. Uses <see cref="ReleaseType"/> (Single/EP/Album). The default.</summary>
+    Cut,
+
+    /// <summary>Single live track plus a hero image. Detail in <c>SessionMetadata</c>.</summary>
+    Session,
+
+    /// <summary>Single long track plus a preprocessed high-resolution waveform datum. Detail in <c>MixMetadata</c>.</summary>
+    Mix
+}