feat(ops): add database backup strategy and log aggregation stack

- Add pg-backup container with daily automated pg_dump (02:00 UTC) and 7-day retention
- Add backup/restore scripts with documented recovery procedure
- Add Loki + Promtail for centralized log aggregation from all Docker containers
- Add Loki as Grafana datasource with correlation ID derived fields
- Add Grafana logs dashboard with volume, error rate, HTTP request, and log viewer panels
- Configure Promtail to parse Pino structured JSON logs with level/context labels
- Enhance LoggerService with string-level formatter and service base field
- Configure 15-day log retention in Loki

Co-Authored-By: Paperclip <noreply@paperclip.ing>

monitoring/promtail/promtail-config.yml

@@ -0,0 +1,66 @@
+server:
+  http_listen_port: 9080
+  grpc_listen_port: 0
+
+positions:
+  filename: /tmp/positions.yaml
+
+clients:
+  - url: http://loki:3100/loki/api/v1/push
+
+scrape_configs:
+  # Scrape Docker container logs
+  - job_name: docker
+    docker_sd_configs:
+      - host: unix:///var/run/docker.sock
+        refresh_interval: 5s
+        filters:
+          - name: network
+            values: ["goodgo-net"]
+    relabel_configs:
+      # Use container name as label
+      - source_labels: ['__meta_docker_container_name']
+        regex: '/(.*)'
+        target_label: 'container'
+      # Add service label from container name (strip goodgo- prefix)
+      - source_labels: ['__meta_docker_container_name']
+        regex: '/goodgo-(.*)'
+        target_label: 'service'
+      # Add compose service label
+      - source_labels: ['__meta_docker_container_label_com_docker_compose_service']
+        target_label: 'compose_service'
+    pipeline_stages:
+      # Try to parse JSON logs (Pino structured output)
+      - json:
+          expressions:
+            level: level
+            msg: msg
+            context: context
+            method: method
+            url: url
+            statusCode: statusCode
+            duration: duration
+            correlationId: correlationId
+            component: component
+            timestamp: time
+      # Map Pino numeric levels to labels
+      - template:
+          source: level
+          template: '{{ if eq .Value "10" }}trace{{ else if eq .Value "20" }}debug{{ else if eq .Value "30" }}info{{ else if eq .Value "40" }}warn{{ else if eq .Value "50" }}error{{ else if eq .Value "60" }}fatal{{ else }}{{ .Value }}{{ end }}'
+      - labels:
+          level:
+          context:
+          component:
+      # Add structured metadata
+      - structured_metadata:
+          method:
+          url:
+          statusCode:
+          correlationId:
+      # Timestamp from Pino output
+      - timestamp:
+          source: timestamp
+          format: RFC3339Nano
+          fallback_formats:
+            - '2006-01-02T15:04:05.999Z07:00'
+          action_on_failure: fudge