feat(backend): AI 反问澄清预检端点——refine 侧结构化 clarify（WFW-9 M1，路线A 两阶段）

润色「再沟通」意见含糊时先反问给选项（路线A：问题走独立非流式 JSON 预检端点，正文仍走
既有 refine 一字不改）。新增：
- ClarifyDecision/ClarifyQuestion/ClarifyOption 结构化 schema（既有 output-schema 处，供
  producer 与端点共用）；clarify_refine.md 教条（含糊→need_clarification+≤1问+2–4锚定选项+
  自由输入；明确→verification 放行；防循环）；注册 clarify_refine_spec(analyst 档,#24)+
  SCHEMA_CATALOG + 重生成金标准。
- clarify_node：build_clarify_request 纯函数(缓存前缀不含易变) + run_clarify（gateway.run
  结构化，判别/校验失败确定性回退 need_clarification=false，只读不写库）。
- POST /projects/{id}/chapters/{no}/refine/clarify → ClarifyDecision（analyst 网关，404/503，
  末尾 commit 记账）。**既有 refine 端点/RefineRequest/Response 完全未改**。
门禁绿：ruff/mypy 227/pytest 900(+test_clarify_spec/_node/style clarify)/alembic 无漂移。

apps/api/ww_api/routers/style.py

@@ -22,10 +22,10 @@ from typing import Annotated, Any
 
 from fastapi import APIRouter, BackgroundTasks, Depends, Request, Response
 from sqlalchemy.ext.asyncio import AsyncSession
-from ww_agents import refiner_spec, style_extract_spec
+from ww_agents import ClarifyDecision, clarify_refine_spec, refiner_spec, style_extract_spec
 from ww_core.domain import JobRepo, ProjectRepo, StyleFingerprintWriteRepo
 from ww_core.domain.style_repo import SqlStyleFingerprintWriteRepo
-from ww_core.orchestrator import run_style_extraction
+from ww_core.orchestrator import run_clarify, run_style_extraction
 from ww_db import get_session
 from ww_llm_gateway import Gateway
 from ww_llm_gateway.types import Block, LlmRequest, Scope
@@ -34,6 +34,7 @@ from ww_shared import AppError, ErrorCode, ErrorEnvelope
 from ww_api.logging_config import get_logger
 from ww_api.schemas.style import (
     DimensionEntry,
+    RefineClarifyRequest,
     RefineRequest,
     RefineResponse,
     StyleFingerprintResponse,
@@ -45,6 +46,7 @@ from ww_api.services.foreshadow_scan import SessionFactory
 from ww_api.services.job_runner import run_job
 from ww_api.services.project_deps import (
     build_gateway_for_tier,
+    get_clarify_gateway,
     get_job_repo,
     get_project_repo,
     get_refine_gateway,
@@ -62,6 +64,7 @@ JobRepoDep = Annotated[JobRepo, Depends(get_job_repo)]
 StyleWriteRepoDep = Annotated[StyleFingerprintWriteRepo, Depends(get_style_write_repo)]
 StyleExtractGatewayDep = Annotated[Gateway, Depends(get_style_extract_gateway)]
 RefineGatewayDep = Annotated[Gateway, Depends(get_refine_gateway)]
+ClarifyGatewayDep = Annotated[Gateway, Depends(get_clarify_gateway)]
 SessionDep = Annotated[AsyncSession, Depends(get_session)]
 SessionFactoryDep = Annotated[SessionFactory, Depends(get_session_factory)]
 
@@ -238,3 +241,59 @@ async def refine_segment(
         has_instruction=body.instruction is not None,
     )
     return RefineResponse(original=body.segment, refined=resp.text)
+
+
+@router.post(
+    "/{project_id}/chapters/{chapter_no}/refine/clarify",
+    responses={
+        404: {"model": ErrorEnvelope, "description": "项目不存在"},
+        503: {"model": ErrorEnvelope, "description": "LLM 不可用"},
+    },
+)
+async def clarify_refine(
+    project_id: uuid.UUID,
+    chapter_no: int,
+    body: RefineClarifyRequest,
+    request: Request,
+    project_repo: ProjectRepoDep,
+    gateway: ClarifyGatewayDep,
+    session: SessionDep,
+) -> ClarifyDecision:
+    """润色预检澄清（WFW-9 M1 路线A 两阶段之「问题」阶段）：非流式 JSON，只判不改。
+
+    独立于既有 refine 端点——只判「作者这条再沟通意见清不清楚」，含糊则反问 1 问 + 给选项，
+    清楚则给确认语放行；**绝不改正文**（正文仍走 refine 端点）。analyst 档（不变量 #2）。
+
+    项目不存在 → 404；无凭据 → 503（dep 解析阶段拦下）。**只读不写库**（不变量 #3）；
+    末尾 `commit()` 让网关 usage_ledger 落库（add-only，否则记账静默丢失，同 refine 纪律）。
+    判别/校验失败在 `run_clarify` 内确定性回退 `need_clarification=false`（不阻塞润色）。
+    """
+    request_id = getattr(request.state, "request_id", None)
+
+    project = await project_repo.get(STUB_OWNER_ID, project_id)
+    if project is None:
+        raise AppError(ErrorCode.NOT_FOUND, f"project not found: {project_id}")
+
+    context = _build_refine_input(body.segment, body.instruction or None)
+    decision = await run_clarify(
+        clarify_refine_spec,  # 不变量 #2：analyst 档，不传 model
+        context=context,
+        gateway=gateway,
+        user_id=STUB_OWNER_ID,
+        project_id=project_id,
+    )
+
+    # 提交边界：只读不写业务表，但网关 ledger add-only → 端点末尾 commit（否则记账丢失）。
+    await session.commit()
+
+    log.info(
+        "refine_clarify_done",
+        project_id=str(project_id),
+        chapter_no=chapter_no,
+        request_id=request_id,
+        segment_len=len(body.segment),
+        instruction_len=len(body.instruction),
+        need_clarification=decision.need_clarification,
+        question_count=len(decision.questions),
+    )
+    return decision