Add commands to manage Postgres read-only replicas

[nholden]

pscale users can manage Postgres read-only replicas from the CLI.

• List replicas with pscale read-only-replica list <database> <branch> --org <org> --format json
• Show a replica with pscale read-only-replica show <database> <branch> <name> --org <org> --format json
• Create a replica with pscale read-only-replica create <database> <branch> <name> --region <region> --org <org> --format json
• Update a replica with pscale read-only-replica update <database> <branch> <name> --replicas 2 --org <org> --format json
• Delete a replica with pscale read-only-replica delete <database> <branch> <name> --org <org> --format json --force

  

[cursor]

Risk: medium. Approved; Cursor Bugbot completed with no findings requiring human review (Security Agent was not present), and no reviewers were assigned.

  

_{Sent by Cursor Approval Agent: cli-reviewer}