grace-plan

<skill> <purpose>Convert one approved active `GraceChangeSpec` into the executable `GraceChangePlan`; do not implement source code.</purpose> <inputs> - Required: `.grace/changes/active/C-CHANGE-ID/spec.xml` - Optional: sibling `design-context.xml` - Current state: `.grace/context`, graph and verification indexes, and their routed documents </inputs> <preflight> - Require `.grace/changes/active/C-CHANGE-ID/spec.xml` with `GraceChangeSpec`, status `approved`, and exactly one matching direct `C-*` wrapper. - Refuse draft, rejected, cancelled, applied, or superseded specs. - Treat optional `design-context.xml` as explanatory; `spec.xml` wins on conflict. - Run `grace lint --path PROJECT --assertions current` before planning and surface stale or invalid active baselines. </preflight> <approved_plan_immutability> - If `plan.xml` already exists with status `approved`, stop before writing. - Do not refresh `BaselineAssertions`, `TargetAssertions`, `DurableScope`, `ObservedWriteScope`, or tasks in place. - Create a new `C-*` bundle and mark the old bundle superseded with an explicit replacement reference. </approved_plan_immutability> <must_do> Produce `plan.xml` from `references/change-plan-template.xml` as draft unless the user explicitly approves the completed plan. Require a matching `C-*` wrapper, meaningful intent, non-empty machine-checkable baseline and target assertions, explicit durable and observed scopes, and unique acyclic `T-NNN` tasks. A scope with no writes must u...