feat: add automated backups and Prometheus/Grafana monitoring stack (Steps 17-18)

Backups: pg_dump scripts with daily/weekly rotation and Cloudflare R2 offsite sync.
Monitoring: Prometheus, Grafana, node-exporter, cAdvisor in docker-compose; /metrics
endpoint activated via prometheus_client.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

monitoring/grafana/provisioning/dashboards/dashboard.yml

@@ -0,0 +1,17 @@
+# File-based dashboard provider
+# Import dashboards via Grafana UI; they'll be saved to the SQLite backend.
+# Pre-built JSON dashboards can be placed in the json/ subdirectory.
+# Docs: https://grafana.com/docs/grafana/latest/administration/provisioning/#dashboards
+
+apiVersion: 1
+
+providers:
+  - name: default
+    orgId: 1
+    folder: ""
+    type: file
+    disableDeletion: false
+    editable: true
+    options:
+      path: /var/lib/grafana/dashboards
+      foldersFromFilesStructure: false

monitoring/grafana/provisioning/datasources/datasource.yml

@@ -0,0 +1,12 @@
+# Auto-provision Prometheus as the default datasource
+# Docs: https://grafana.com/docs/grafana/latest/administration/provisioning/#datasources
+
+apiVersion: 1
+
+datasources:
+  - name: Prometheus
+    type: prometheus
+    access: proxy
+    url: http://prometheus:9090
+    isDefault: true
+    editable: true

monitoring/prometheus.yml

@@ -0,0 +1,36 @@
+# Prometheus configuration for Orion platform
+# Docs: https://prometheus.io/docs/prometheus/latest/configuration/configuration/
+
+global:
+  scrape_interval: 15s
+  evaluation_interval: 15s
+
+scrape_configs:
+  # Orion API — /metrics endpoint (prometheus_client)
+  - job_name: "orion-api"
+    metrics_path: /metrics
+    static_configs:
+      - targets: ["api:8000"]
+        labels:
+          service: "orion-api"
+
+  # Node Exporter — host-level CPU, RAM, disk metrics
+  - job_name: "node-exporter"
+    static_configs:
+      - targets: ["node-exporter:9100"]
+        labels:
+          service: "node-exporter"
+
+  # cAdvisor — per-container resource metrics
+  - job_name: "cadvisor"
+    static_configs:
+      - targets: ["cadvisor:8080"]
+        labels:
+          service: "cadvisor"
+
+  # Prometheus self-monitoring
+  - job_name: "prometheus"
+    static_configs:
+      - targets: ["localhost:9090"]
+        labels:
+          service: "prometheus"