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-agent-cursor/__tests__/cursor-agent.test.ts

@@ -1,12 +1,11 @@
 import { describe, expect, test } from "bun:test";
-import type { ExtractContext, ExtractFn } from "@uncaged/workflow-runtime";
+import type { ExtractFn } from "@uncaged/workflow-runtime";
 import type * as z from "zod/v4";
 import { createCursorAgent, validateCursorAgentConfig } from "../src/index.js";
 
 const testExtract: ExtractFn = async <T extends Record<string, unknown>>(
   _schema: z.ZodType<T>,
-  _prompt: string,
-  _ctx: ExtractContext,
+  _contentHash: string,
 ): Promise<{ meta: T; contentPayload: string; refs: string[] }> => ({
   meta: { workspace: "/tmp" } as unknown as T,
   contentPayload: "",

packages/workflow-agent-cursor/src/index.ts

@@ -1,4 +1,4 @@
-import type { AgentFn, ExtractContext } from "@uncaged/workflow-runtime";
+import type { AgentFn } from "@uncaged/workflow-runtime";
 import { buildAgentPrompt, type SpawnCliError, spawnCli } from "@uncaged/workflow-util-agent";
 import * as z from "zod/v4";
 
@@ -44,16 +44,7 @@ export function createCursorAgent(config: CursorAgentConfig): AgentFn {
   const timeoutMs = config.timeout > 0 ? config.timeout : null;
 
   return async (ctx) => {
-    const extractCtx: ExtractContext = {
-      ...ctx,
-      agentContent: "",
-    };
-    const extracted = await config.extract(
-      cursorWorkspaceSchema,
-      "From the thread context, determine the absolute filesystem path where the project/repository is located.",
-      extractCtx,
-    );
-    const { workspace } = extracted.meta;
+    const { workspace } = ctx.currentRole as unknown as { workspace: string };
     const fullPrompt = await buildAgentPrompt(ctx);
     const args = [
       "-p",