Update Implementation Plan

The update-implementation-plan skill generates machine-readable implementation plans by updating existing plan files with new or modified requirements for features, refactoring, or infrastructure changes. It's designed for AI agents and technical teams who need deterministic, structured plans with explicit tasks, measurable completion criteria, and specific file paths that can be automatically parsed and executed. The skill solves the problem of creating ambiguous or incomplete implementation documentation by enforcing a rigid, templated structure with unambiguous language and validation rules suitable for autonomous processing.