fix(reliability): Remove cutoffTime filter to prevent data loss in outbox poller

CRITICAL: Previous cutoffTime logic (occurred_at >= now-5min) silently dropped
messages older than 5 minutes forever, contradicting Outbox Pattern's guarantee
of eventual delivery for stuck messages.

Changes:
- DapperOutboxMessageReader: Remove cutoffTime parameter, process ALL unpublished
- OutboxPollerJob: Remove cutoffTime calculation, process all messages by occurred_at
- Tests: Remove cutoff scenario (no longer applicable); keep normal + max-attempts
- Comments: Document monitoring approach (alert if pending > 5 min) as separate concern

AGENTS.md v16.0 Checklist:
✅ Safety: No partial success (no silent data loss)
✅ Audit: Evidence tracked (all messages eventually processed)
✅ Right Way: Root cause fixed (was processing-logic bug, not test-logic bug)

Test results: 2/2 passing (normal path, max-attempts DQ)
Validation gate: Outbox/Inbox crash-recovery ✅ RESTORED

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/KArtSell.BuildingBlocks/Reliability/DapperOutboxMessageReader.cs

@@ -17,7 +17,6 @@ public sealed class DapperOutboxMessageReader(IDbConnectionFactory connectionFac
             attempt as Attempt
         from building_blocks.outbox_message
         where published_at is null
-          and occurred_at >= @CutoffTime
         order by occurred_at asc
         limit @BatchSize
         """;
@@ -36,7 +35,6 @@ public sealed class DapperOutboxMessageReader(IDbConnectionFactory connectionFac
         """;
 
     public async Task<IReadOnlyList<OutboxMessageRow>> GetUnpublishedAsync(
-        DateTimeOffset cutoffTime,
         int batchSize,
         CancellationToken cancellationToken)
     {
@@ -44,7 +42,7 @@ public sealed class DapperOutboxMessageReader(IDbConnectionFactory connectionFac
         var messages = await connection.QueryAsync<OutboxMessageRow>(
             new CommandDefinition(
                 SelectUnpublishedSql,
-                new { CutoffTime = cutoffTime, BatchSize = batchSize },
+                new { BatchSize = batchSize },
                 cancellationToken: cancellationToken));
         return messages.ToList();
     }

src/KArtSell.Host/Jobs/OutboxPollerJob.cs

@@ -43,9 +43,10 @@ public sealed class OutboxPollerJob(
     public async Task ExecuteAsync(CancellationToken cancellationToken = default)
     {
         var now = clock.UtcNow;
-        var cutoffTime = now.AddMinutes(-5);
 
-        var messages = await reader.GetUnpublishedAsync(cutoffTime, DefaultBatchSize, cancellationToken);
+        // Process all unpublished messages ordered by occurred_at (oldest first).
+        // Monitoring: alert if any message pending > 5 min (see dashboard/alerts).
+        var messages = await reader.GetUnpublishedAsync(DefaultBatchSize, cancellationToken);
 
         var failureCount = 0;
         foreach (var message in messages)

tests/KArtSell.Integration.Tests/OutboxPollerJobTests.cs

@@ -104,89 +104,6 @@ public sealed class OutboxPollerJobTests : IAsyncLifetime
         }
     }
 
-    [Fact]
-    public async Task ExecuteAsync_SkipsMessagesBeyondCutoff_OnlyProcessesRecentMessages()
-    {
-        // Arrange: Insert two messages - one old, one recent
-        var oldMessageId = Guid.NewGuid();
-        var recentMessageId = Guid.NewGuid();
-        var now = _clock.UtcNow;
-        const string payload = """{"data":"test"}""";
-        var hash = ContentHasher.Sha256(payload);
-
-        await using (var connection = await _connectionFactory.OpenAsync(CancellationToken.None))
-        {
-            await connection.ExecuteAsync("""
-                insert into building_blocks.outbox_message
-                (message_id, event_type, schema_version, payload_json, correlation_id, occurred_at, payload_hash)
-                values (@MessageId, @EventType, 1, cast(@PayloadJson as jsonb), @CorrelationId, @OccurredAt, @Hash)
-                """,
-                new
-                {
-                    MessageId = oldMessageId,
-                    EventType = "OldEvent",
-                    PayloadJson = payload,
-                    CorrelationId = Guid.NewGuid().ToString(),
-                    OccurredAt = now.AddMinutes(-10),
-                    Hash = hash
-                });
-
-            await connection.ExecuteAsync("""
-                insert into building_blocks.outbox_message
-                (message_id, event_type, schema_version, payload_json, correlation_id, occurred_at, payload_hash)
-                values (@MessageId, @EventType, 1, cast(@PayloadJson as jsonb), @CorrelationId, @OccurredAt, @Hash)
-                """,
-                new
-                {
-                    MessageId = recentMessageId,
-                    EventType = "RecentEvent",
-                    PayloadJson = payload,
-                    CorrelationId = Guid.NewGuid().ToString(),
-                    OccurredAt = now.AddMinutes(-2),
-                    Hash = hash
-                });
-        }
-
-        var reader = new DapperOutboxMessageReader(_connectionFactory);
-        var job = new OutboxPollerJob(reader, _clock, _logger);
-
-        // Act
-        await job.ExecuteAsync(CancellationToken.None);
-
-        // Assert: Only recent message should be published (and have inbox entry)
-        await using (var connection = await _connectionFactory.OpenAsync(CancellationToken.None))
-        {
-            var oldPublished = await connection.QuerySingleOrDefaultAsync<DateTime?>(
-                "select published_at from building_blocks.outbox_message where message_id = @MessageId",
-                new { MessageId = oldMessageId });
-            var recentPublished = await connection.QuerySingleOrDefaultAsync<DateTime?>(
-                "select published_at from building_blocks.outbox_message where message_id = @MessageId",
-                new { MessageId = recentMessageId });
-
-            Assert.Null(oldPublished);
-            Assert.NotNull(recentPublished);
-
-            // Verify inbox entry exists ONLY for recent message
-            var oldInbox = await connection.QuerySingleOrDefaultAsync<Guid?>(
-                "select message_id from building_blocks.inbox_message where message_id = @MessageId",
-                new { MessageId = oldMessageId });
-            var recentInbox = await connection.QuerySingleOrDefaultAsync<Guid?>(
-                "select message_id from building_blocks.inbox_message where message_id = @MessageId",
-                new { MessageId = recentMessageId });
-
-            Assert.Null(oldInbox);
-            Assert.Equal(recentMessageId, recentInbox);
-        }
-
-        // Cleanup
-        await using (var connection = await _connectionFactory.OpenAsync(CancellationToken.None))
-        {
-            await connection.ExecuteAsync(
-                "delete from building_blocks.outbox_message where message_id in (@OldId, @RecentId)",
-                new { OldId = oldMessageId, RecentId = recentMessageId });
-        }
-    }
-
     [Fact]
     public async Task ExecuteAsync_SkipsMessagesExceedingMaxAttempts_LogsAsDeadLetter()
     {