feat(email): add tenant draft persistence

Add owner-filtered, job-cascading private draft storage with reversible SQLite and MariaDB migration paths. No API or UI exposes draft content yet.

JobTrackerApi/Migrations/20260810075206_AddEmailDrafts.cs

@@ -0,0 +1,83 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace JobTrackerApi.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddEmailDrafts : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            if (ActiveProvider.Contains("MySql", StringComparison.OrdinalIgnoreCase))
+            {
+                migrationBuilder.Sql("""
+                    CREATE TABLE `EmailDrafts` (
+                        `Id` char(36) CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL,
+                        `OwnerUserId` varchar(255) NOT NULL,
+                        `JobApplicationId` int NOT NULL,
+                        `Provider` varchar(32) NOT NULL,
+                        `To` varchar(320) NOT NULL,
+                        `Subject` varchar(998) NOT NULL,
+                        `BodyText` longtext NOT NULL,
+                        `ThreadId` varchar(512) NULL,
+                        `Revision` bigint NOT NULL,
+                        `CreatedAtUtc` datetime(6) NOT NULL,
+                        `UpdatedAtUtc` datetime(6) NOT NULL,
+                        CONSTRAINT `PK_EmailDrafts` PRIMARY KEY (`Id`),
+                        CONSTRAINT `FK_EmailDrafts_JobApplications_JobApplicationId`
+                            FOREIGN KEY (`JobApplicationId`) REFERENCES `JobApplications` (`Id`) ON DELETE CASCADE
+                    ) CHARACTER SET=utf8mb4;
+                    """);
+            }
+            else
+            {
+            migrationBuilder.CreateTable(
+                name: "EmailDrafts",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "TEXT", nullable: false),
+                    OwnerUserId = table.Column<string>(type: "TEXT", maxLength: 255, nullable: false),
+                    JobApplicationId = table.Column<int>(type: "INTEGER", nullable: false),
+                    Provider = table.Column<string>(type: "TEXT", maxLength: 32, nullable: false),
+                    To = table.Column<string>(type: "TEXT", maxLength: 320, nullable: false),
+                    Subject = table.Column<string>(type: "TEXT", maxLength: 998, nullable: false),
+                    BodyText = table.Column<string>(type: "TEXT", nullable: false),
+                    ThreadId = table.Column<string>(type: "TEXT", maxLength: 512, nullable: true),
+                    Revision = table.Column<long>(type: "INTEGER", nullable: false),
+                    CreatedAtUtc = table.Column<DateTime>(type: "TEXT", nullable: false),
+                    UpdatedAtUtc = table.Column<DateTime>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_EmailDrafts", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_EmailDrafts_JobApplications_JobApplicationId",
+                        column: x => x.JobApplicationId,
+                        principalTable: "JobApplications",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+            }
+
+            migrationBuilder.CreateIndex(
+                name: "IX_EmailDrafts_JobApplicationId",
+                table: "EmailDrafts",
+                column: "JobApplicationId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_EmailDrafts_OwnerUserId_JobApplicationId_UpdatedAtUtc",
+                table: "EmailDrafts",
+                columns: new[] { "OwnerUserId", "JobApplicationId", "UpdatedAtUtc" });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "EmailDrafts");
+        }
+    }
+}

JobTrackerApi/Migrations/JobTrackerContextModelSnapshot.cs

@@ -1098,6 +1098,61 @@ namespace JobTrackerApi.Migrations
                     b.ToTable("CvVariantVersions");
                 });
 
+            modelBuilder.Entity("JobTrackerApi.Models.EmailDraft", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("BodyText")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("JobApplicationId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("OwnerUserId")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Provider")
+                        .IsRequired()
+                        .HasMaxLength(32)
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("Revision")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Subject")
+                        .IsRequired()
+                        .HasMaxLength(998)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ThreadId")
+                        .HasMaxLength(512)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("To")
+                        .IsRequired()
+                        .HasMaxLength(320)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("UpdatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("JobApplicationId");
+
+                    b.HasIndex("OwnerUserId", "JobApplicationId", "UpdatedAtUtc");
+
+                    b.ToTable("EmailDrafts");
+                });
+
             modelBuilder.Entity("JobTrackerApi.Models.EmailSendAttempt", b =>
                 {
                     b.Property<Guid>("Id")
@@ -2446,6 +2501,17 @@ namespace JobTrackerApi.Migrations
                     b.Navigation("CvVariant");
                 });
 
+            modelBuilder.Entity("JobTrackerApi.Models.EmailDraft", b =>
+                {
+                    b.HasOne("JobTrackerApi.Models.JobApplication", "JobApplication")
+                        .WithMany()
+                        .HasForeignKey("JobApplicationId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("JobApplication");
+                });
+
             modelBuilder.Entity("JobTrackerApi.Models.EmailSendAttempt", b =>
                 {
                     b.HasOne("JobTrackerApi.Models.JobApplication", "JobApplication")