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/tests/test_chapter_read_view.py

@@ -0,0 +1,62 @@
+"""章节读路径 prepare_chapter_read_view：不写库、临时物化串用于列表/详情。"""
+
+from unittest.mock import MagicMock, patch
+
+from app.features.memoir.reading_segment_materialize import (
+    chapter_meets_minimum_display,
+)
+from app.features.memoir.service import prepare_chapter_read_view
+
+
+def test_prepare_not_dirty_no_override() -> None:
+    ch = MagicMock()
+    ch.markdown_compose_dirty = False
+    ch.reading_segments_json = None
+    ch.story_links = [MagicMock()]
+    c, md = prepare_chapter_read_view(ch)
+    assert c is ch
+    assert md is None
+
+
+def test_prepare_dirty_with_snapshot_no_override() -> None:
+    ch = MagicMock()
+    ch.markdown_compose_dirty = True
+    ch.reading_segments_json = [{"story_id": "s1", "body_markdown": "x" * 400}]
+    ch.story_links = [MagicMock()]
+    c, md = prepare_chapter_read_view(ch)
+    assert md is None
+
+
+def test_prepare_dirty_no_snapshot_no_links_no_override() -> None:
+    ch = MagicMock()
+    ch.markdown_compose_dirty = True
+    ch.reading_segments_json = None
+    ch.story_links = []
+    c, md = prepare_chapter_read_view(ch)
+    assert md is None
+
+
+def test_prepare_dirty_no_snapshot_with_links_uses_materialize() -> None:
+    ch = MagicMock()
+    ch.markdown_compose_dirty = True
+    ch.reading_segments_json = None
+    ch.story_links = [MagicMock()]
+    fake_md = "正文" * 200
+    with patch(
+        "app.features.memoir.service.materialize_chapter_markdown_from_loaded_chapter",
+        return_value=fake_md,
+    ) as m:
+        c, md = prepare_chapter_read_view(ch)
+    m.assert_called_once_with(ch)
+    assert md == fake_md.strip()
+    assert c is ch
+
+
+def test_chapter_meets_minimum_uses_override() -> None:
+    ch = MagicMock()
+    ch.canonical_markdown = ""
+    long_md = "字" * 400
+    assert (
+        chapter_meets_minimum_display(ch, canonical_markdown_override=long_md) is True
+    )
+    assert chapter_meets_minimum_display(ch, canonical_markdown_override="短") is False