feat(email): include drafts in user exports

Export readable private draft content only through existing owner-filtered encrypted and daily export boundaries, with cross-tenant regression coverage.

JobTrackerApi.Tests/BackupControllerTests.cs

@@ -36,7 +36,8 @@ public sealed class BackupControllerTests
         await using var db = CreateDb();
         db.Companies.Add(new Company { Name = "Acme", OwnerUserId = "user-1" });
         var job = new JobApplication { JobTitle = "Backend Developer", OwnerUserId = "user-1" };
-        db.JobApplications.Add(job);
+        var otherJob = new JobApplication { JobTitle = "Other tenant role", OwnerUserId = "user-2" };
+        db.JobApplications.AddRange(job, otherJob);
         await db.SaveChangesAsync();
         db.EmailSendAttempts.Add(new EmailSendAttempt
         {
@@ -51,6 +52,32 @@ public sealed class BackupControllerTests
             CreatedAtUtc = DateTime.UtcNow,
             CompletedAtUtc = DateTime.UtcNow,
         });
+        db.EmailDrafts.Add(new EmailDraft
+        {
+            Id = Guid.NewGuid(),
+            OwnerUserId = "user-1",
+            JobApplicationId = job.Id,
+            Provider = "gmail",
+            To = "recipient@example.test",
+            Subject = "Synthetic export subject",
+            BodyText = "Synthetic readable draft body.",
+            ThreadId = "synthetic-thread",
+            Revision = 3,
+            CreatedAtUtc = DateTime.UtcNow.AddMinutes(-5),
+            UpdatedAtUtc = DateTime.UtcNow,
+        });
+        db.EmailDrafts.Add(new EmailDraft
+        {
+            Id = Guid.NewGuid(),
+            OwnerUserId = "user-2",
+            JobApplicationId = otherJob.Id,
+            Provider = "microsoft",
+            To = "other@example.test",
+            Subject = "Other tenant subject",
+            BodyText = "Other tenant private body.",
+            CreatedAtUtc = DateTime.UtcNow,
+            UpdatedAtUtc = DateTime.UtcNow,
+        });
         await db.SaveChangesAsync();
 
         var provider = DataProtectionProvider.Create(new DirectoryInfo(Path.Combine(Path.GetTempPath(), $"jobtracker-tests-{Guid.NewGuid():N}")));
@@ -70,6 +97,12 @@ public sealed class BackupControllerTests
         Assert.Equal("gmail", attempt.GetProperty("Provider").GetString());
         Assert.Equal("sent", attempt.GetProperty("Status").GetString());
         Assert.False(attempt.TryGetProperty("PayloadHash", out _));
+        var draft = Assert.Single(document.RootElement.GetProperty("Data").GetProperty("EmailDrafts").EnumerateArray());
+        Assert.Equal("recipient@example.test", draft.GetProperty("To").GetString());
+        Assert.Equal("Synthetic export subject", draft.GetProperty("Subject").GetString());
+        Assert.Equal("Synthetic readable draft body.", draft.GetProperty("BodyText").GetString());
+        Assert.Equal("synthetic-thread", draft.GetProperty("ThreadId").GetString());
+        Assert.Equal(3, draft.GetProperty("Revision").GetInt64());
     }
 
     private static JobTrackerContext CreateDb()