feat(api): 叙事 prompt、职业上下文、读路径章节、WS 解耦与错误脱敏

- 回忆录：事实边界补充允许清单；传记文体示例与 JSON 叙事要求对齐
- default 职业提示 occupation_context；cadre/military 退休语境
- GET 章节读路径零写入，prepare_chapter_read_view + markdown_for_response
- 文本归一抽到 core/text_normalize；移除弃用 reply 策略与 recompose_chapters_for_story
- ConversationService：WS 连接/用户段落/结束对话；对外错误固定文案
- 测试：HTTP 脱敏契约、章节读视图、occupation 与 background_voice

api/app/agents/memoir/narrative_agent.py

@@ -68,6 +68,7 @@ class NarrativeAgent:
         birth_year: Optional[int] = None,
         llm: Any = None,
         background_voice: str = "default",
+        occupation: str = "",
     ) -> str:
         """将新对话改写为叙述。若无 LLM 则直接拼接。
 
@@ -88,6 +89,7 @@ class NarrativeAgent:
                     user_profile=user_profile,
                     birth_year=birth_year,
                     background_voice=background_voice,
+                    occupation=occupation,
                 )
                 max_tokens = 8192
                 agent_name = "NarrativeAgent.generate_narrative_merge"
@@ -100,6 +102,7 @@ class NarrativeAgent:
                     user_profile=user_profile,
                     birth_year=birth_year,
                     background_voice=background_voice,
+                    occupation=occupation,
                 )
                 max_tokens = 4096
                 agent_name = "NarrativeAgent.generate_narrative"