Grace Plan Agent Skill

<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• Refuse draft, rejected, cancelled, applied, or superseded specs.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• Create a new C-* bundle and mark the old bundle superseded with an explicit replacement reference.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 use an explicit <None /> marker; prose such as "none" is invalid. Every task has one Title, one DependsOn, non-empty acceptance criteria, and non-empty verification commands. Surface stale-state and coexistence warnings, and reject unsupported scope glob syntax instead of guessing.

</must_do>

<command_phase_rules>

• current is an active-baseline preflight and is valid only before observed writes begin.
• baseline is the selected pre-edit gate, target is selected post-edit evidence, and final is the outer apply/archive gate owned by grace-execute.
• MustPassCommand contains leaf project evidence such as tests, typecheck, build, format, or package checks. Never place grace lint, grace status, or another GRACE lifecycle command inside it.
• Never put --assertions current in TargetAssertions or in task verification that runs after writes. Use selected target/final lint externally instead.

</command_phase_rules>

<validation>

• Active-baseline preflight: grace lint --path PROJECT --assertions current
• Parallel safety: grace lint --path PROJECT --parallel-preflight
• Recommend grace status --path PROJECT --json after approval.

</validation>

<hard_rules>

Do not implement code, silently approve a plan, overwrite an approved plan, or mutate current graph/verification artifacts while planning. Semantic anchors are canonical XML tags, never attributes.

</hard_rules>

</skill>