feat(db-hardening): Add database persistence, backups, and MinIO assets storage

Database Hardening:
- Add docker-compose.db.yml with persistent PostgreSQL volume
- Add automatic DB backups every 12h (7 days, 4 weeks, 6 months retention)
- Add MinIO S3-compatible storage for assets

Assets Migration:
- Add MinIO client (lib/assets_client.py) for upload/delete
- Update upload endpoint to use MinIO (with local fallback)
- Add migration 043_asset_urls_to_text.sql for full HTTPS URLs
- Simplify normalizeAssetUrl for S3 URLs

Recovery:
- Add seed_full_city_reset.py for emergency city recovery
- Add DB_RESTORE.md with backup restore instructions
- Add SEED_RECOVERY.md with recovery procedures
- Add INFRA_ASSETS_MINIO.md with MinIO setup guide

Task: TASK_PHASE_DATABASE_HARDENING_AND_ASSETS_MIGRATION_v1

docker-compose.db.yml

@@ -0,0 +1,83 @@
+version: "3.9"
+
+services:
+  # PostgreSQL Database with persistent storage
+  db:
+    image: postgres:15-alpine
+    container_name: daarion-postgres
+    restart: unless-stopped
+    environment:
+      POSTGRES_DB: daarion
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
+    ports:
+      - "5432:5432"
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+      - ./migrations:/docker-entrypoint-initdb.d:ro
+    networks:
+      - dagi-network
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres -d daarion"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 30s
+
+  # Automatic database backups
+  db-backup:
+    image: prodrigestivill/postgres-backup-local:latest
+    container_name: daarion-db-backup
+    restart: unless-stopped
+    environment:
+      POSTGRES_HOST: db
+      POSTGRES_DB: daarion
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
+      SCHEDULE: "@every 12h"
+      BACKUP_KEEP_DAYS: 7
+      BACKUP_KEEP_WEEKS: 4
+      BACKUP_KEEP_MONTHS: 6
+    volumes:
+      - ./db_backups:/backups
+    depends_on:
+      - db
+    networks:
+      - dagi-network
+
+  # MinIO S3-compatible object storage for assets
+  minio:
+    image: minio/minio:latest
+    container_name: daarion-minio
+    restart: unless-stopped
+    command: server /data --console-address ":9001"
+    environment:
+      MINIO_ROOT_USER: ${MINIO_ROOT_USER:-assets-admin}
+      MINIO_ROOT_PASSWORD: ${MINIO_ROOT_PASSWORD:-change-me-strong-password}
+    ports:
+      - "9000:9000"  # S3 API
+      - "9001:9001"  # Web console
+    volumes:
+      - minio_data:/data
+    networks:
+      - dagi-network
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:9000/minio/health/live"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 10s
+
+volumes:
+  pgdata:
+    driver: local
+    name: daarion_pgdata
+  minio_data:
+    driver: local
+    name: daarion_minio_data
+
+networks:
+  dagi-network:
+    external: true
+    name: dagi-network
+