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/cli-workflow/src/moderator/evaluate.ts

@@ -0,0 +1,53 @@
+import type { Target } from "@uncaged/workflow-protocol";
+import mustache from "mustache";
+
+import type { EvaluateResult, Result } from "./types.js";
+
+// Disable HTML escaping — prompts are plain text, not HTML.
+mustache.escape = (text: string) => text;
+
+const START_ROLE = "$START";
+const UNIT_STATUS = "_";
+
+type LastOutput = Record<string, unknown>;
+
+const STATUS_KEY = "$status";
+
+export function evaluate(
+  graph: Record<string, Record<string, Target>>,
+  lastRole: string,
+  lastOutput: LastOutput,
+): Result<EvaluateResult, Error> {
+  const status =
+    lastRole === START_ROLE
+      ? UNIT_STATUS
+      : typeof lastOutput[STATUS_KEY] === "string"
+        ? (lastOutput[STATUS_KEY] as string)
+        : UNIT_STATUS;
+
+  const roleTargets = graph[lastRole];
+  if (roleTargets === undefined) {
+    return {
+      ok: false,
+      error: new Error(`no transitions defined for role "${lastRole}"`),
+    };
+  }
+
+  const target = roleTargets[status];
+  if (target === undefined) {
+    return {
+      ok: false,
+      error: new Error(`no transition for role "${lastRole}" with status "${status}"`),
+    };
+  }
+
+  try {
+    const prompt = mustache.render(target.prompt, lastOutput);
+    return { ok: true, value: { role: target.role, prompt } };
+  } catch (error) {
+    return {
+      ok: false,
+      error: error instanceof Error ? error : new Error(String(error)),
+    };
+  }
+}