feat: add postgresql backup & restore snippets

# Postgresql Backup and Restore in Docker

## Make pg backup

```shell

docker exec -e PGPASSWORD='<SuperSecure>' <ContainerName> \

  pg_dump -U <PostgresRole> -d <PostgresDB> -Fc -f /tmp/database.dump

```

## Copy backup to root

```shell

docker cp <ContainerName>:/tmp/database.dump /root/database.dump

```

## Stop and remove old container

```shell

docker stop <ContainerName>

docker rm <ContainerName>

```

## Remove old database files

```shell

rm -rf /mnt/<PostgresDBDatadir>/

mkdir /mnt/<PostgresDBDatadir>/

chown 999 /mnt/<PostgresDBDatadir>/

chmod 700 /mnt/<PostgresDBDatadir>/

```

## Start new container

```shell

docker run \

  --name <ContainerName> \

  --detach \

  --restart unless-stopped \

  --network <ContainerNetwork> \

  --volume /mnt/<PostgresDBDatadir>:/var/lib/postgresql/data \

  --env POSTGRES_DB=<PostgresDB> \

  --env POSTGRES_USER=<PostgresRole> \

  --env POSTGRES_PASSWORD=<SuperSecure>

  docker.io/library/postgres:17

```

## Copy backup to new container

```shell

docker cp /root/database.dump <ContainerName>:/tmp/database.dump

```

## Verify role and db

```shell

docker exec -e PGPASSWORD='<SuperSecure>' <ContainerName> \

  psql -U <PostgresRole> -c "CREATE ROLE <PostgresRole> WITH LOGIN PASSWORD '<SuperSecure>';"

docker exec -e PGPASSWORD='<SuperSecure>' <ContainerName> \

  psql -U <PostgresRole> -c "CREATE DATABASE <PostgresDB> OWNER <PostgresRole>;"

```

## Restore backup

```shell

docker exec -e PGPASSWORD='<SuperSecure>' <ContainerName> \

  pg_restore -U <PostgresRole> -d <PostgresDB> -Fc /tmp/database.dump

```