Add pg-boss background job queue with session expiry

Add @trails-cool/jobs package wrapping pg-boss for durable background job
execution using the existing PostgreSQL database. Wire up planner session
expiry as the first scheduled job (hourly, 7-day TTL) — this was previously
dead code that never ran. Add placeholder worker to journal for future
Komoot import and federation jobs.

Infrastructure: grant grafana_reader access to pgboss schema, add job queue
health panels to Service Health dashboard, add failed job alert.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

infrastructure/grafana/dashboards/service-health.json

@@ -479,6 +479,69 @@
           "legendFormat": "in-flight"
         }
       ]
+    },
+    {
+      "title": "Job Queue \u2014 Status",
+      "description": "Background job counts by state from pg-boss. Queries the pgboss.job table via the PostgreSQL datasource.",
+      "type": "table",
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 72
+      },
+      "targets": [
+        {
+          "datasource": {
+            "type": "postgres",
+            "uid": "postgres"
+          },
+          "rawSql": "SELECT state, count(*) AS count FROM pgboss.job GROUP BY state ORDER BY count DESC",
+          "format": "table"
+        }
+      ]
+    },
+    {
+      "title": "Job Queue \u2014 Failed Jobs (last 24h)",
+      "description": "Recently failed background jobs with error details.",
+      "type": "table",
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 72
+      },
+      "targets": [
+        {
+          "datasource": {
+            "type": "postgres",
+            "uid": "postgres"
+          },
+          "rawSql": "SELECT name, state, createdon, completedon, output::text AS error FROM pgboss.job WHERE state = 'failed' AND completedon > now() - interval '24 hours' ORDER BY completedon DESC LIMIT 20",
+          "format": "table"
+        }
+      ]
+    },
+    {
+      "title": "Job Queue \u2014 Completed/hour",
+      "description": "Background jobs completed per hour over the last 24 hours.",
+      "type": "timeseries",
+      "gridPos": {
+        "h": 8,
+        "w": 24,
+        "x": 0,
+        "y": 80
+      },
+      "targets": [
+        {
+          "datasource": {
+            "type": "postgres",
+            "uid": "postgres"
+          },
+          "rawSql": "SELECT date_trunc('hour', completedon) AS time, name, count(*) AS completed FROM pgboss.job WHERE state = 'completed' AND completedon > now() - interval '24 hours' GROUP BY 1, 2 ORDER BY 1",
+          "format": "time_series"
+        }
+      ]
     }
   ]
 }

infrastructure/grafana/provisioning/alerting/alerts.yml

@@ -152,6 +152,36 @@ groups:
         annotations:
           summary: "Crash signature detected in application logs"
 
+      - uid: background-job-failures
+        title: Background job failures
+        condition: C
+        noDataState: OK
+        data:
+          - refId: A
+            relativeTimeRange: { from: 3600, to: 0 }
+            datasourceUid: postgres
+            model:
+              rawSql: "SELECT count(*) AS failed FROM pgboss.job WHERE state = 'failed' AND completedon > now() - interval '1 hour'"
+              format: table
+          - refId: B
+            datasourceUid: __expr__
+            model:
+              type: reduce
+              expression: A
+              reducer: last
+          - refId: C
+            datasourceUid: __expr__
+            model:
+              type: threshold
+              expression: B
+              conditions:
+                - evaluator: { params: [0], type: gt }
+                  operator: { type: and }
+                  reducer: { type: last }
+        for: 0s
+        annotations:
+          summary: "Background jobs have failed in the last hour — check Grafana Service Health dashboard"
+
       - uid: caddy-502-rate
         title: Caddy 502 errors detected
         condition: B

infrastructure/postgres/init-grafana-user.sql

@@ -31,5 +31,10 @@ BEGIN
     GRANT SELECT ON ALL TABLES IN SCHEMA journal TO grafana_reader;
     ALTER DEFAULT PRIVILEGES IN SCHEMA journal GRANT SELECT ON TABLES TO grafana_reader;
   END IF;
+  IF EXISTS (SELECT 1 FROM information_schema.schemata WHERE schema_name = 'pgboss') THEN
+    GRANT USAGE ON SCHEMA pgboss TO grafana_reader;
+    GRANT SELECT ON ALL TABLES IN SCHEMA pgboss TO grafana_reader;
+    ALTER DEFAULT PRIVILEGES IN SCHEMA pgboss GRANT SELECT ON TABLES TO grafana_reader;
+  END IF;
 END
 $$;