feat: MetaGarbage round-to-round and server-restart persistence

Content.Server.Database/Migrations/Postgres/20260418115645_AddMetaGarbage.cs

@@ -0,0 +1,45 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace Content.Server.Database.Migrations.Postgres
+{
+    /// <inheritdoc />
+    public partial class AddMetaGarbage : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "meta_garbage",
+                columns: table => new
+                {
+                    meta_garbage_id = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    map_prototype = table.Column<string>(type: "character varying(256)", maxLength: 256, nullable: false),
+                    data = table.Column<string>(type: "text", nullable: false),
+                    map_version = table.Column<int>(type: "integer", nullable: false),
+                    saved_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_meta_garbage", x => x.meta_garbage_id);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_meta_garbage_map_prototype",
+                table: "meta_garbage",
+                column: "map_prototype",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "meta_garbage");
+        }
+    }
+}

Content.Server.Database/Migrations/Postgres/PostgresServerDbContextModelSnapshot.cs

@@ -892,6 +892,44 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.ToTable("mentor_help_tickets", (string)null);
                 });
 
+            modelBuilder.Entity("Content.Server.Database.MetaGarbageEntry", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasColumnName("meta_garbage_id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Data")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("data");
+
+                    b.Property<string>("MapPrototype")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)")
+                        .HasColumnName("map_prototype");
+
+                    b.Property<int>("MapVersion")
+                        .HasColumnType("integer")
+                        .HasColumnName("map_version");
+
+                    b.Property<DateTime>("SavedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("saved_at");
+
+                    b.HasKey("Id")
+                        .HasName("PK_meta_garbage");
+
+                    b.HasIndex("MapPrototype")
+                        .IsUnique()
+                        .HasDatabaseName("IX_meta_garbage_map_prototype");
+
+                    b.ToTable("meta_garbage", (string)null);
+                });
+
             modelBuilder.Entity("Content.Server.Database.PlayTime", b =>
                 {
                     b.Property<int>("Id")