Prepare a blue-green VPS deployment

Design a repeatable, project-specific deployment that keeps the current version serving traffic until a replacement has started and passed verification. Blue- green reduces application downtime, but does not by itself guarantee zero downtime: database changes, singleton work, shared state, and infrastructure limits can still require coordination or a maintenance window.

Read and apply task-completion using the skill loader or sibling file; report if unavailable. Complete and validate the requested preparation artifacts. A verified preparation task can be complete without a live deployment: list operator prerequisites separately, and do not connect to a host or deploy merely to eliminate a preparation-only next step.

Establish the project and deployment model