feat(frontend): 润色再沟通接入 AI 反问澄清——选项芯片 + 折答案回炉（WFW-9 M1）

RefinePanel「再沟通」升级为对话式：意见含糊/极短(门控 <10 字，或点「帮我理清方向」)时先调
clarify 预检端点让 AI 反问，渲染 ChoiceChips 选项芯片(+自由输入兜底)；作者选/答后
foldClarifications 把答案折进 instruction，再走既有 refine 回炉(零迁移)。清晰意见直接回炉、
不交往返税；预检失败=放行(useClarify 视 error/异常为 needClarification=false，不阻塞润色)。
新增：lib/workbench/clarify.ts(VM 类型+foldClarifications+needsClarifyGate 纯逻辑) +
useClarify(SSE 外调映射 snake→VM) + ChoiceChips.tsx；gen:api 重生成客户端。
门禁绿：tsc/lint/vitest 654(+clarify/useClarify 18 例)/build/coverage 95.36%。

apps/web/lib/workbench/clarify.test.ts

@@ -0,0 +1,90 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  foldClarifications,
+  needsClarifyGate,
+  type ClarifyAnswer,
+} from "./clarify";
+
+describe("foldClarifications", () => {
+  it("原意见在前，每条澄清另起一行并保序", () => {
+    const answers: ClarifyAnswer[] = [
+      { question: "这段谁在说话？", answer: "主角内心独白" },
+      { question: "结尾要留钩子吗？", answer: "留一个悬念" },
+    ];
+
+    const result = foldClarifications("收紧节奏", answers);
+
+    expect(result).toBe(
+      "收紧节奏\n已澄清：这段谁在说话？ → 主角内心独白\n已澄清：结尾要留钩子吗？ → 留一个悬念",
+    );
+  });
+
+  it("无回答时原样返回去空白后的 instruction", () => {
+    expect(foldClarifications("  收紧节奏  ", [])).toBe("收紧节奏");
+  });
+
+  it("instruction 为空时只输出澄清行", () => {
+    const answers: ClarifyAnswer[] = [
+      { question: "谁在说话？", answer: "配角旁白" },
+    ];
+    expect(foldClarifications("   ", answers)).toBe("已澄清：谁在说话？ → 配角旁白");
+  });
+
+  it("跳过空/纯空白回答的条目", () => {
+    const answers: ClarifyAnswer[] = [
+      { question: "Q1", answer: "  " },
+      { question: "Q2", answer: "有效回答" },
+    ];
+    expect(foldClarifications("原意见", answers)).toBe(
+      "原意见\n已澄清：Q2 → 有效回答",
+    );
+  });
+
+  it("问题为空（自由输入）时省略问题只留答案", () => {
+    const answers: ClarifyAnswer[] = [{ question: "  ", answer: "就按我说的改" }];
+    expect(foldClarifications("原意见", answers)).toBe(
+      "原意见\n已澄清：就按我说的改",
+    );
+  });
+
+  it("去除问题与答案两端空白", () => {
+    const answers: ClarifyAnswer[] = [
+      { question: "  谁在说话？  ", answer: "  主角  " },
+    ];
+    expect(foldClarifications("x", answers)).toBe("x\n已澄清：谁在说话？ → 主角");
+  });
+
+  it("不可变：不修改入参数组", () => {
+    const answers: ClarifyAnswer[] = [{ question: "Q", answer: "A" }];
+    const snapshot = JSON.parse(JSON.stringify(answers));
+    foldClarifications("原意见", answers);
+    expect(answers).toEqual(snapshot);
+  });
+
+  it("全部为空回答且 instruction 为空时返回空串", () => {
+    expect(foldClarifications("", [{ question: "Q", answer: "" }])).toBe("");
+  });
+});
+
+describe("needsClarifyGate", () => {
+  it("去空白后长度小于 minChars 时需要预检", () => {
+    expect(needsClarifyGate("改一下", 8)).toBe(true);
+  });
+
+  it("恰好等于 minChars 时不需预检（边界）", () => {
+    expect(needsClarifyGate("12345678", 8)).toBe(false);
+  });
+
+  it("超过 minChars 时不需预检", () => {
+    expect(needsClarifyGate("这是一段足够清晰具体的润色意见", 8)).toBe(false);
+  });
+
+  it("纯空白按空计（长度 0 < minChars）需预检", () => {
+    expect(needsClarifyGate("      ", 8)).toBe(true);
+  });
+
+  it("先去两端空白再计长度", () => {
+    expect(needsClarifyGate("  改  ", 2)).toBe(true);
+  });
+});