When running Strapi in a clustered setup (e.g. multiple containers in Kubernetes), each instance currently attempts to run migrations on startup. This leads to race conditions and unpredictable behavior. Ideally, migrations should be triggered manually during deployment, e.g. via a CI/CD upgrade job.

Feature Request:

1. Add a global flag or environment variable to disable all automatic migrations (internal, schema, and user-defined).

2. Provide a CLI command to run all pending migrations manually, outside of instance startup.