Migrate from Crunchy Data PostgreSQL Operator to Percona PostgreSQL Operator: Standby Cluster Method

A step-by-step guide for migrating from the Crunchy Data PostgreSQL Operator to the Percona PostgreSQL Operator v3.0.0 on Kubernetes using the standby cluster method. Since Percona's operator is a hard fork of Crunchy's, both share Patroni, pgBackRest, and PgBouncer. The process involves deploying SeaweedFS as a shared S3-compatible pgBackRest repository, creating a Percona cluster in standby mode that replicates from the Crunchy primary via WAL archiving and streaming replication, then promoting it with near-zero downtime. The guide covers all 11 steps including TLS certificate handling, replication lag verification, cutover, rollback procedures, and common troubleshooting scenarios.