修复：CI 部署环境与 ref 错配、迁移碎片化、图片意图 source_span、章节物化脏版式、会话历史与本地语音不一致

新增：TTS 上传 COS 与分片、章节 reading_segments 物化与快照、markdown 清洗、会话消息 repository、语音 store 重构与相关测试

api/tests/test_chapter_cover_enqueue.py

@@ -8,10 +8,16 @@ from app.tasks.chapter_cover_enqueue import (
 )
 
 
+def _md_with_n_inline_images(n: int) -> str:
+    lines = [f"![c](asset://a{i})" for i in range(n)]
+    return "\n\n".join(lines) + "\n\n正文"
+
+
 def _eligible_pipeline_chapter():
     ch = MagicMock()
     ch.cover_asset_id = None
-    ch.canonical_markdown = "some body"
+    # 章节封面：正文内 asset 插图需 >3 才入队
+    ch.canonical_markdown = _md_with_n_inline_images(4)
     ch.images = []
     return ch
 
@@ -69,6 +75,20 @@ def test_try_enqueue_true_when_eligible_and_nx_ok(mock_load, mock_redis, mock_ge
     r.set.assert_called_once()
 
 
+@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
+@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
+@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
+def test_try_enqueue_false_when_inline_images_not_enough(
+    mock_load, mock_redis, mock_gen_task
+):
+    ch = _eligible_pipeline_chapter()
+    ch.canonical_markdown = _md_with_n_inline_images(3)
+    mock_load.return_value = ch
+    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is False
+    mock_gen_task.delay.assert_not_called()
+    mock_redis.assert_not_called()
+
+
 @patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
 @patch("app.tasks.chapter_cover_enqueue.redis.from_url")
 @patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")