refactor: rename workflow-agent-kit → workflow-util-agent, merge workflow-moderator into cli-workflow

- Rename packages/workflow-agent-kit → packages/workflow-util-agent
- Update all imports, tsconfig references, docs
- Delete dead file packages/workflow-util-agent/src/build-agent-prompt.ts
- Merge workflow-moderator (62 LOC) into cli-workflow/src/moderator/
- Move workflow-moderator to legacy-packages/
- Add mustache dependency to cli-workflow
- Update publish-all.mjs

Fixes #512

packages/workflow-agent-hermes/src/hermes.ts

@@ -5,7 +5,7 @@ import {
   buildContinuationPrompt,
   buildRolePrompt,
   createAgent,
-} from "@uncaged/workflow-agent-kit";
+} from "@uncaged/workflow-util-agent";
 import { createLogger } from "@uncaged/workflow-util";
 
 import { HermesAcpClient } from "./acp-client.js";