n8n: surface real per-workflow evidence on the integration status page

Fleet Ops integration status no longer depends only on a config
boolean or the most recent outbox event: N8nIntegrationStatus now
reports per-canonical-workflow evidence (last successful outbox
delivery for the return workflow, latest service-triggered
data_quality_scan_run for the scan workflow, latest
n8n_workflow_failure_registered for the error handler, and "not built"
for the still-blocked RAGcore sync), plus an error-handler summary
(total failures registered, latest failure + which workflow).

Automation page renders this as a localized workflow table (EN/NL/FR)
with technical workflow names tucked under a "Technical details"
disclosure, matching the existing progressive-disclosure pattern.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/app/schemas.py

@@ -223,6 +223,18 @@ class SearchResponse(BaseModel):
     results: list[SearchResultItem]
 
 
+class N8nWorkflowEvidence(BaseModel):
+    name: str
+    built: bool
+    last_seen_at: datetime | None
+
+
+class N8nErrorHandlerStatus(BaseModel):
+    total_failures_registered: int
+    latest_failure_at: datetime | None
+    latest_failure_workflow: str | None
+
+
 class N8nIntegrationStatus(BaseModel):
     configured: bool
     dispatch_enabled: bool
@@ -233,6 +245,10 @@ class N8nIntegrationStatus(BaseModel):
     succeeded: int
     latest_success_at: datetime | None
     latest_failure_at: datetime | None
+    expected_workflow_count: int
+    known_workflow_count: int
+    workflows: list[N8nWorkflowEvidence]
+    error_handler: N8nErrorHandlerStatus
 
 
 class McpHubIntegrationStatus(BaseModel):

backend/app/services/integration_status.py

@@ -6,11 +6,21 @@ from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
 from app.core.config import get_settings
+from app.models.audit import AuditEvent
 from app.models.outbox import OutboxEvent
-from app.schemas import N8nIntegrationStatus
+from app.schemas import N8nErrorHandlerStatus, N8nIntegrationStatus, N8nWorkflowEvidence
 
 settings = get_settings()
 
+# The 4 canonical Fleet Ops n8n workflows (see n8n/workflows/MANIFEST.md). Workflow 3
+# (RAGcore Procedure Sync) is not built yet, so it always reports no evidence.
+_CANONICAL_WORKFLOWS = (
+    "Fleet Ops — Vehicle Return Orchestration",
+    "Fleet Ops — Scheduled Data Quality Scan",
+    "Fleet Ops — RAGcore Procedure Sync",
+    "Fleet Ops — Workflow Error Handler",
+)
+
 
 def derive_n8n_status(db: Session) -> N8nIntegrationStatus:
     counts: dict[str, int] = dict(
@@ -42,6 +52,52 @@ def derive_n8n_status(db: Session) -> N8nIntegrationStatus:
     else:
         state = "no_evidence"
 
+    # Scheduled scan evidence: only service-triggered runs count as n8n evidence, not
+    # runs an operator triggered manually from the Data Quality page.
+    latest_scan_at = db.scalar(
+        select(func.max(AuditEvent.occurred_at)).where(
+            AuditEvent.action == "data_quality_scan_run",
+            AuditEvent.actor_type == "service",
+        )
+    )
+
+    # Error handler evidence: registrations posted by the "Fleet Ops — Workflow Error
+    # Handler" n8n workflow itself, which also doubles as proof that workflow is wired
+    # up and firing correctly.
+    total_failures_registered = (
+        db.scalar(
+            select(func.count(AuditEvent.id)).where(
+                AuditEvent.action == "n8n_workflow_failure_registered"
+            )
+        )
+        or 0
+    )
+    latest_failure_row = db.execute(
+        select(AuditEvent.occurred_at, AuditEvent.after_json)
+        .where(AuditEvent.action == "n8n_workflow_failure_registered")
+        .order_by(AuditEvent.occurred_at.desc())
+        .limit(1)
+    ).first()
+    latest_handler_failure_at = latest_failure_row[0] if latest_failure_row else None
+    latest_handler_failure_workflow = (
+        (latest_failure_row[1] or {}).get("workflow_name") if latest_failure_row else None
+    )
+
+    evidence_by_workflow = {
+        "Fleet Ops — Vehicle Return Orchestration": latest_success_at,
+        "Fleet Ops — Scheduled Data Quality Scan": latest_scan_at,
+        "Fleet Ops — RAGcore Procedure Sync": None,
+        "Fleet Ops — Workflow Error Handler": latest_handler_failure_at,
+    }
+    workflows = [
+        N8nWorkflowEvidence(
+            name=name,
+            built=name != "Fleet Ops — RAGcore Procedure Sync",
+            last_seen_at=evidence_by_workflow[name],
+        )
+        for name in _CANONICAL_WORKFLOWS
+    ]
+
     return N8nIntegrationStatus(
         configured=bool(settings.n8n_webhook_url),
         dispatch_enabled=settings.n8n_dispatch_enabled,
@@ -52,4 +108,12 @@ def derive_n8n_status(db: Session) -> N8nIntegrationStatus:
         succeeded=succeeded,
         latest_success_at=latest_success_at,
         latest_failure_at=latest_failure_at,
+        expected_workflow_count=len(_CANONICAL_WORKFLOWS),
+        known_workflow_count=sum(1 for w in workflows if w.last_seen_at is not None),
+        workflows=workflows,
+        error_handler=N8nErrorHandlerStatus(
+            total_failures_registered=total_failures_registered,
+            latest_failure_at=latest_handler_failure_at,
+            latest_failure_workflow=latest_handler_failure_workflow,
+        ),
     )