Phase 5: Outbox DLQ, Monitoring, Consumer-Registry

- Migration 0092: DLQ columns (error_message, failed_at) + consumer_inbox RLS fix
- outbox.py: DLQ logic, replay functions, stats, consumer registry
- app/routes/outbox.py: 5 API endpoints (stats, failed, replay, replay-all, consumer-registry)
- outbox_deliveries tracking per consumer handler
- 18/18 tests passing

app/models/outbox.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 import uuid
 from datetime import datetime
 
-from sqlalchemy import DateTime, Integer, String, func
+from sqlalchemy import DateTime, Integer, String, Text, func
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.dialects.postgresql import UUID as PGUUID
 from sqlalchemy.orm import Mapped, mapped_column
@@ -54,3 +54,26 @@ class EventOutbox(Base):
     published_at: Mapped[datetime | None] = mapped_column(
         DateTime(timezone=True), nullable=True,
     )
+    # Envelope columns (migration 0075)
+    aggregate_type: Mapped[str | None] = mapped_column(
+        String(100), nullable=True,
+    )
+    aggregate_id: Mapped[uuid.UUID | None] = mapped_column(
+        PGUUID(as_uuid=True), nullable=True,
+    )
+    occurred_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(),
+    )
+    correlation_id: Mapped[uuid.UUID | None] = mapped_column(
+        PGUUID(as_uuid=True), nullable=True,
+    )
+    schema_version: Mapped[int] = mapped_column(
+        Integer, nullable=False, server_default="1",
+    )
+    # Phase 5: DLQ columns
+    error_message: Mapped[str | None] = mapped_column(
+        Text, nullable=True,
+    )
+    failed_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True,
+    )