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。

packages/agents/ww_agents/__init__.py

@@ -16,6 +16,9 @@ from .schemas import (
     CharacterizationIssue,
     CharacterizationReview,
     CharacterRelation,
+    ClarifyDecision,
+    ClarifyOption,
+    ClarifyQuestion,
     Conflict,
     ConflictType,
     ContinuationResult,
@@ -60,6 +63,7 @@ from .specs import (
     brainstorm_spec,
     character_gen_spec,
     characterization_spec,
+    clarify_refine_spec,
     continue_spec,
     continuity_spec,
     de_ai_spec,
@@ -93,6 +97,9 @@ __all__ = [
     "CharacterizationIssue",
     "CharacterizationReview",
     "CharacterRelation",
+    "ClarifyDecision",
+    "ClarifyOption",
+    "ClarifyQuestion",
     "Conflict",
     "ConflictType",
     "ContinuationResult",
@@ -133,6 +140,7 @@ __all__ = [
     "brainstorm_spec",
     "character_gen_spec",
     "characterization_spec",
+    "clarify_refine_spec",
     "continue_spec",
     "continuity_spec",
     "de_ai_spec",