Initial commit: QMDSearch 分层信息检索服务

- FastAPI + Qdrant + Redis + Ollama 技术栈
- L1→L2→L3→chunk 四层分层检索（dense + sparse RRF 融合）
- 文档三级总结与 2.5 级回退
- query 解析路由与分类
- /admin 管理页面

tests/test_summarizer.py

@@ -0,0 +1,75 @@
+"""Summarizer 标题树接入的单元测试"""
+
+from app.core.summarizer import Summarizer
+from app.models.document import SummaryLevel
+
+
+class FakeOllama:
+    """记录调用次数的 OllamaClient 替身"""
+
+    def __init__(self) -> None:
+        self.prompts: list[str] = []
+
+    async def generate(self, prompt: str) -> str:
+        self.prompts.append(prompt)
+        return "LLM 生成结果"
+
+
+def _structured_text() -> str:
+    """构造带标题结构且长度 ≥ 500 的文档（不触发 2.5 回退）"""
+    paragraph = "这是章节正文内容，包含足够多的信息量。" * 10
+    return f"# 安装指南\n{paragraph}\n## 环境准备\n{paragraph}\n## 安装步骤\n{paragraph}"
+
+
+class TestStructuredDocument:
+    """结构化文档：L2 直接使用标题树，不调 LLM"""
+
+    async def test_l2_from_headings_skips_llm(self):
+        ollama = FakeOllama()
+        summarizer = Summarizer(ollama=ollama)  # type: ignore[arg-type]
+
+        summary = await summarizer.summarize(_structured_text(), title="安装文档")
+
+        assert summary.level == SummaryLevel.L3
+        # L1 + L3 两次调用，跳过了 L2 的 LLM 调用
+        assert len(ollama.prompts) == 2
+        # 大纲由标题树渲染，包含标题文本与层级缩进
+        assert summary.l2_outline is not None
+        assert "- 安装指南" in summary.l2_outline
+        assert "  - 环境准备" in summary.l2_outline
+        assert "  - 安装步骤" in summary.l2_outline
+        assert summary.l2_outline != "LLM 生成结果"
+        # L3 的 prompt 中注入了标题树大纲
+        assert "安装指南" in ollama.prompts[1]
+
+
+class TestPlainDocument:
+    """无结构文档：L2 回退 LLM 生成"""
+
+    async def test_l2_falls_back_to_llm(self):
+        ollama = FakeOllama()
+        summarizer = Summarizer(ollama=ollama)  # type: ignore[arg-type]
+        text = "这是一段没有标题结构的正文内容，" * 40  # 640 字符，不触发 2.5 回退
+
+        summary = await summarizer.summarize(text, title="")
+
+        assert summary.level == SummaryLevel.L3
+        # L1 + L2 + L3 三次调用
+        assert len(ollama.prompts) == 3
+        assert summary.l2_outline == "LLM 生成结果"
+
+
+class TestFallbackUnaffected:
+    """2.5 级回退逻辑不受标题树改造影响"""
+
+    async def test_short_structured_text_still_fallback(self):
+        ollama = FakeOllama()
+        summarizer = Summarizer(ollama=ollama)  # type: ignore[arg-type]
+        text = "# 标题一\n简短内容。\n# 标题二\n简短内容。"
+
+        summary = await summarizer.summarize(text, title="")
+
+        assert summary.level == SummaryLevel.L2_HALF
+        assert summary.l2_outline is None
+        # L1 + L2.5 两次调用
+        assert len(ollama.prompts) == 2