feat: add four-phase role description (identity/prepare/execute/report)

- Extend RoleDefinition with identity, prepare, execute, report fields
- Make systemPrompt optional (nullable) for four-phase workflows
- Update ROLE_DEFINITION JSON Schema (all new fields optional)
- Update validate.ts to accept new fields
- Update workflow.ts to strip null fields before CAS storage
- Update thread read to prefer identity over systemPrompt
- Add --version flag to uwf CLI
- Bump all packages to 0.5.0

Refs #359

packages/workflow-protocol/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@uncaged/workflow-protocol",
-  "version": "0.1.0",
+  "version": "0.5.0",
   "files": [
     "src",
     "dist",

packages/workflow-protocol/src/schemas.ts

@@ -2,10 +2,14 @@ import type { JSONSchema } from "@uncaged/json-cas";
 
 const ROLE_DEFINITION: JSONSchema = {
   type: "object",
-  required: ["description", "systemPrompt", "outputSchema"],
+  required: ["description", "outputSchema"],
   properties: {
     description: { type: "string" },
     systemPrompt: { type: "string" },
+    identity: { type: "string" },
+    prepare: { type: "string" },
+    execute: { type: "string" },
+    report: { type: "string" },
     outputSchema: { type: "string", format: "cas_ref" },
   },
   additionalProperties: false,

packages/workflow-protocol/src/types.ts

@@ -18,7 +18,11 @@ export type StepRecord = {
 
 export type RoleDefinition = {
   description: string;
-  systemPrompt: string;
+  systemPrompt: string | null;
+  identity: string | null;
+  prepare: string | null;
+  execute: string | null;
+  report: string | null;
   outputSchema: CasRef;
 };