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/BackgroundWorkerTenantTests.cs

@@ -121,6 +121,9 @@ public sealed class BackgroundWorkerTenantTests
             db.EmailSendAttempts.AddRange(
                 new EmailSendAttempt { Id = Guid.NewGuid(), OwnerUserId = "user-1", JobApplicationId = jobs[0].Id, Provider = "gmail", ClientRequestId = Guid.NewGuid().ToString(), PayloadHash = new string('a', 64), Status = EmailSendStatuses.Sent, CreatedAtUtc = DateTime.UtcNow },
                 new EmailSendAttempt { Id = Guid.NewGuid(), OwnerUserId = "user-2", JobApplicationId = jobs[1].Id, Provider = "microsoft", ClientRequestId = Guid.NewGuid().ToString(), PayloadHash = new string('b', 64), Status = EmailSendStatuses.Failed, FailureCategory = "rejected", CreatedAtUtc = DateTime.UtcNow });
+            db.EmailDrafts.AddRange(
+                Draft("user-1", jobs[0].Id, "one@example.test", "Private draft one"),
+                Draft("user-2", jobs[1].Id, "two@example.test", "Private draft two"));
             await db.SaveChangesAsync();
         }
         var environment = new Mock<IHostEnvironment>();
@@ -148,6 +151,10 @@ public sealed class BackgroundWorkerTenantTests
                 var attempt = Assert.Single(rootElement.GetProperty("EmailSendAttempts").EnumerateArray());
                 Assert.Equal(owner == "user-1" ? "gmail" : "microsoft", attempt.GetProperty("Provider").GetString());
                 Assert.False(attempt.TryGetProperty("PayloadHash", out _));
+                var draft = Assert.Single(rootElement.GetProperty("EmailDrafts").EnumerateArray());
+                Assert.Equal(owner == "user-1" ? "one@example.test" : "two@example.test", draft.GetProperty("To").GetString());
+                Assert.Equal(owner == "user-1" ? "Private draft one" : "Private draft two", draft.GetProperty("BodyText").GetString());
+                Assert.Equal(1, draft.GetProperty("Revision").GetInt64());
             }
             owners.Sort(StringComparer.Ordinal);
             Assert.Equal(new[] { "user-1", "user-2" }, owners);
@@ -159,6 +166,20 @@ public sealed class BackgroundWorkerTenantTests
         }
     }
 
+    private static EmailDraft Draft(string ownerUserId, int jobApplicationId, string recipient, string body) => new()
+    {
+        Id = Guid.NewGuid(),
+        OwnerUserId = ownerUserId,
+        JobApplicationId = jobApplicationId,
+        Provider = ownerUserId == "user-1" ? "gmail" : "microsoft",
+        To = recipient,
+        Subject = "Synthetic export subject",
+        BodyText = body,
+        ThreadId = "synthetic-thread",
+        CreatedAtUtc = DateTime.UtcNow.AddMinutes(-5),
+        UpdatedAtUtc = DateTime.UtcNow,
+    };
+
     [Fact]
     public async Task Enrichment_processes_both_owners_only_through_fake_ai()
     {