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>

docs/backup-restore.md

@@ -0,0 +1,102 @@
+# Database Backup & Restore Procedures
+
+## Overview
+
+Automated daily PostgreSQL backups run inside the `pg-backup` Docker container using `pg_dump` with custom format compression. Backups are stored in the `pg_backups` Docker volume.
+
+## Backup Configuration
+
+| Setting | Default | Environment Variable |
+|---------|---------|---------------------|
+| Schedule | Daily at 02:00 UTC | Cron in `pg-backup` service |
+| Retention | 7 days | `BACKUP_RETENTION_DAYS` |
+| Format | Custom (`pg_dump --format=custom`) | — |
+| Compression | Level 6 | — |
+| Storage | `pg_backups` Docker volume | — |
+
+## Listing Backups
+
+```bash
+docker exec goodgo-pg-backup ls -lh /backups/
+```
+
+## Manual Backup
+
+```bash
+docker exec goodgo-pg-backup /scripts/pg-backup.sh
+```
+
+## Restore Procedure
+
+### 1. Identify the backup to restore
+
+```bash
+docker exec goodgo-pg-backup ls -lht /backups/
+```
+
+### 2. Stop application services
+
+```bash
+docker compose stop ai-services
+# Stop any NestJS API processes
+```
+
+### 3. Run restore
+
+```bash
+docker exec -it goodgo-pg-backup /scripts/pg-restore.sh /backups/goodgo_YYYYMMDD_HHMMSS.sql.gz
+```
+
+The restore script will:
+- Terminate active database connections
+- Drop and recreate the database
+- Restore from the selected backup
+
+### 4. Verify restore
+
+```bash
+docker exec goodgo-postgres psql -U goodgo -d goodgo -c '\dt'
+docker exec goodgo-postgres psql -U goodgo -d goodgo -c 'SELECT count(*) FROM "User";'
+```
+
+### 5. Run Prisma migrations (if needed)
+
+```bash
+pnpm prisma migrate deploy
+```
+
+### 6. Restart services
+
+```bash
+docker compose up -d
+```
+
+## Backup Verification
+
+Check the backup log:
+
+```bash
+docker exec goodgo-pg-backup cat /var/log/pg-backup.log
+```
+
+Verify backup integrity without restoring:
+
+```bash
+docker exec goodgo-pg-backup pg_restore --list /backups/goodgo_YYYYMMDD_HHMMSS.sql.gz
+```
+
+## Disaster Recovery
+
+For complete data loss (volume destroyed):
+
+1. Retrieve backup from external storage (if configured)
+2. Recreate the `pg_backups` volume and copy backup file in
+3. Follow the restore procedure above
+
+## Log Aggregation
+
+Logs are aggregated via Loki + Promtail and viewable in Grafana:
+
+- **Grafana**: http://localhost:3002 (dashboard: "GoodGo - Logs")
+- **Loki**: http://localhost:3100
+- **Log retention**: 15 days (configured in `monitoring/loki/loki-config.yml`)