refactor: simplify ExtractFn to (schema, contentHash)

- Remove extractPrompt from RoleDefinition
- Remove ExtractContext type
- ExtractFn now takes (schema, contentHash) instead of (schema, prompt, ExtractContext)
- createExtract reads CAS content by hash, keeps ReAct loop with cas_get
- Coder schema uses .describe() for phase hash hint
- All role definitions, CLI templates, and skill output updated

Refs #180, closes #174, closes #181

packages/workflow-template-develop/src/roles/planner.ts

@@ -44,8 +44,6 @@ Order phases so earlier steps unblock later ones. Cover root cause, edge cases,
 export const plannerRole: RoleDefinition<PlannerMeta> = {
   description: "Breaks the task into sequential phases for the coder.",
   systemPrompt: PLANNER_SYSTEM,
-  extractPrompt:
-    "Extract the implementation phases from the agent's output. Each phase has a hash (the CAS content-hash returned by the cas put command) and a title (one-line summary).",
   schema: plannerMetaSchema,
   extractRefs: (meta) => meta.phases.map((p) => p.hash),
 };