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

docs/builtin-agent-research.md

@@ -78,9 +78,9 @@ Agent 解析优先级（`resolveAgentConfig`）：
 
 #### 环境变量：Storage Root
 
-文档中写的 `UWF_STORAGE_ROOT` **在当前代码中不存在**。实际优先级（`workflow-agent-kit` / `cli-workflow` 一致）：
+文档中写的 `UWF_STORAGE_ROOT` **在当前代码中不存在**。实际优先级（`workflow-util-agent` / `cli-workflow` 一致）：
 
-```33:43:packages/workflow-agent-kit/src/storage.ts
+```33:43:packages/workflow-util-agent/src/storage.ts
 export function resolveStorageRoot(): string {
   const internal = process.env.UNCAGED_WORKFLOW_STORAGE_ROOT;
   if (internal !== undefined && internal !== "") {
@@ -107,7 +107,7 @@ Agent 子进程通过继承的 `process.env` 与父 CLI 共享同一 storage roo
 
 ### Q2: createAgent 工厂
 
-workflow-agent-kit 的 `createAgent` 做了什么？它的完整生命周期是什么？
+workflow-util-agent 的 `createAgent` 做了什么？它的完整生命周期是什么？
 
 **调研要点：**
 - `AgentOptions` 类型的 `run` 和 `continue` 回调签名
@@ -119,7 +119,7 @@ workflow-agent-kit 的 `createAgent` 做了什么？它的完整生命周期是
 
 #### 类型定义
 
-```4:35:packages/workflow-agent-kit/src/types.ts
+```4:35:packages/workflow-util-agent/src/types.ts
 export type AgentContext = ModeratorContext & {
   threadId: ThreadId;
   role: string;
@@ -156,7 +156,7 @@ export type AgentOptions = {
 
 #### 生命周期（按执行顺序）
 
-```101:152:packages/workflow-agent-kit/src/run.ts
+```101:152:packages/workflow-util-agent/src/run.ts
 export function createAgent(options: AgentOptions): () => Promise<void> {
   return async function main(): Promise<void> {
     const { threadId, role } = parseArgv(process.argv);
@@ -197,7 +197,7 @@ export function createAgent(options: AgentOptions): () => Promise<void> {
 
 #### StepNode 写入结构
 
-```44:68:packages/workflow-agent-kit/src/run.ts
+```44:68:packages/workflow-util-agent/src/run.ts
 async function writeStepNode(options: {
   store: AgentStore["store"];
   schemas: AgentStore["schemas"];
@@ -274,7 +274,7 @@ export type StepContext = Omit<StepRecord, "output"> & {
 
 `buildContextWithMeta` 还返回 `meta`：
 
-```148:154:packages/workflow-agent-kit/src/context.ts
+```148:154:packages/workflow-util-agent/src/context.ts
 export type BuildContextMeta = {
   storageRoot: string;
   store: Store;
@@ -337,7 +337,7 @@ async function resolveFrontmatterRef(..., frontmatter: unknown): Promise<CasRef>
 
 #### Frontmatter fast-path（createAgent 实际使用的路径）
 
-```148:195:packages/workflow-agent-kit/src/frontmatter.ts
+```148:195:packages/workflow-util-agent/src/frontmatter.ts
 export async function tryFrontmatterFastPath(
   raw: string,
   outputSchema: CasRef,
@@ -357,7 +357,7 @@ export async function tryFrontmatterFastPath(
 
 #### LLM extract fallback（已实现但未接入 createAgent）
 
-```135:181:packages/workflow-agent-kit/src/extract.ts
+```135:181:packages/workflow-util-agent/src/extract.ts
 export async function extract(
   rawOutput: string,
   outputSchema: CasRef,
@@ -374,7 +374,7 @@ export async function extract(
 
 #### Correction prompt（retry）
 
-```125:128:packages/workflow-agent-kit/src/run.ts
+```125:128:packages/workflow-util-agent/src/run.ts
 const correctionMessage =
   "Your previous response did not contain valid YAML frontmatter matching the role schema.\n" +
   "You MUST begin your response with a YAML frontmatter block (--- delimited).\n" +
@@ -425,7 +425,7 @@ export type WorkflowConfig = {
 
 #### resolveModel
 
-```32:50:packages/workflow-agent-kit/src/extract.ts
+```32:50:packages/workflow-util-agent/src/extract.ts
 export function resolveModel(config: WorkflowConfig, alias: ModelAlias): ResolvedLlmProvider {
   const modelEntry = config.models[alias];
   const providerEntry = config.providers[modelEntry.provider];
@@ -438,7 +438,7 @@ export function resolveModel(config: WorkflowConfig, alias: ModelAlias): Resolve
 
 Extract 专用别名解析：
 
-```18:30:packages/workflow-agent-kit/src/extract.ts
+```18:30:packages/workflow-util-agent/src/extract.ts
 export function resolveExtractModelAlias(config: WorkflowConfig): ModelAlias {
   return config.modelOverrides?.extract ?? (config.models.extract ? "extract" : config.models.default ? "default" : config.defaultModel);
 }
@@ -448,7 +448,7 @@ export function resolveExtractModelAlias(config: WorkflowConfig): ModelAlias {
 
 #### chatCompletionText
 
-```87:124:packages/workflow-agent-kit/src/extract.ts
+```87:124:packages/workflow-util-agent/src/extract.ts
 async function chatCompletionText(
   provider: ResolvedLlmProvider,
   messages: Array<{ role: "system" | "user"; content: string }>,
@@ -463,7 +463,7 @@ async function chatCompletionText(
 | 多模态 | **无**（仅 text `content`） |
 | Extract 专用 | `response_format: { type: "json_object" }` |
 
-builtin agent 的 run loop 需要**新写**带 `tools` 的 completion 客户端（可放在 `workflow-agent-builtin` 或扩展 `workflow-agent-kit` 的 `llm/` 模块），不能复用当前 `chatCompletionText` 而不改。
+builtin agent 的 run loop 需要**新写**带 `tools` 的 completion 客户端（可放在 `workflow-agent-builtin` 或扩展 `workflow-util-agent` 的 `llm/` 模块），不能复用当前 `chatCompletionText` 而不改。
 
 ---
 
@@ -609,7 +609,7 @@ flowchart TB
     Loop --> Detail
   end
 
-  subgraph kit ["workflow-agent-kit"]
+  subgraph kit ["workflow-util-agent"]
     Ctx["buildContextWithMeta"]
     FM["tryFrontmatterFastPath"]
     Persist["persistStep"]
@@ -630,7 +630,7 @@ flowchart TB
   Spawn -->|"stdout: step hash"| Step
 ```
 
-**新包**：`packages/workflow-agent-builtin`，bin `uwf-builtin`，仅依赖 `workflow-agent-kit`、`workflow-protocol`、`workflow-util`（可选 `@uncaged/json-cas` 写 detail schema）。
+**新包**：`packages/workflow-agent-builtin`，bin `uwf-builtin`，仅依赖 `workflow-util-agent`、`workflow-protocol`、`workflow-util`（可选 `@uncaged/json-cas` 写 detail schema）。
 
 **分层**：