feat(api): 访谈路径轻量门控、Memoir Phase1 批处理与叙事/记忆管线加固

- 新增 utterance_substance：短时/应答/元话语可跳过记忆检索、阶段 LLM 与资料抽取 LLM；可配置
- 输入归一化：LLM 模式默认仅语音/ASR；配置项写入 .env.example
- Memoir Phase1：可选 batch LLM 一次性抽取+分类（失败回退逐段）；Extraction 空槽位时阶段与 current_stage 对齐，prompt 约束收紧
- 叙事与忠实度：narrative_safety、证据重叠/场合锚点、标题 slots 与履历短语 grounded；fidelity 解析失败 fail-open 可配置
- 章节管线：锁 TTL 上调、锁竞争 Celery 重试、Phase2 immediate singleflight 等；story_pipeline_sync / chapter_compose / memoir_tasks 联动
- Memory：compaction / repo / summarizer / evidence 小修；事实 FTS 未命中是否回退最近事实可配置
- 新增 memoir_pipeline_trace；补充 memoir_reliability 文档与多项回归/门控测试

api/app/features/conversation/input_normalize.py

@@ -29,7 +29,12 @@ def _llm_normalize_chat_input(text: str, llm: Any) -> str | None:
     )
 
 
-def normalize_chat_input_for_agent(text: str, *, llm: Any | None = None) -> str:
+def normalize_chat_input_for_agent(
+    text: str,
+    *,
+    llm: Any | None = None,
+    is_from_voice: bool = False,
+) -> str:
     """
     聊天侧单一出口：编排层与 InterviewAgent 共用。
 
@@ -37,6 +42,7 @@ def normalize_chat_input_for_agent(text: str, *, llm: Any | None = None) -> str:
     - off：原文
     - rules：仅规则
     - llm：先规则，再（可选）LLM；无 llm 或失败则保留规则结果
+    - chat_input_normalize_llm_voice_only：mode=llm 时仅 is_from_voice 为真才调用 LLM
     """
     if not settings.chat_input_normalize_enabled:
         return text or ""
@@ -48,7 +54,11 @@ def normalize_chat_input_for_agent(text: str, *, llm: Any | None = None) -> str:
     if mode != "llm":
         return base
 
-    refined = _llm_normalize_chat_input(base, llm)
+    effective_llm = llm
+    if settings.chat_input_normalize_llm_voice_only and not is_from_voice:
+        effective_llm = None
+
+    refined = _llm_normalize_chat_input(base, effective_llm)
     if refined is not None:
         return refined
     return base