Initial project setup: NF Hotel Data Analysis API

- Add project structure with domain-driven design organization
- Implement FastAPI endpoints for hotel booking reports
- Add data cleaning, statistics, and LLM report generation services
- Include configuration management and security utilities
- Add repository layer for bookings and metadata access
- Setup testing framework with conftest.py
- Include example files and documentation

tests/test_llm_report.py

@@ -0,0 +1,80 @@
+import httpx
+import pytest
+
+from nf_hotel_api.services.llm_report import LLMReportService, LLMServiceError
+
+
+def test_strip_thinking_removes_think_block():
+    raw = "<think>internal reasoning that must not leak</think>## Report\nBody text"
+    assert LLMReportService._strip_thinking(raw) == "## Report\nBody text"
+
+
+def test_strip_thinking_is_noop_when_no_think_block():
+    raw = "## Report\nBody text"
+    assert LLMReportService._strip_thinking(raw) == raw
+
+
+class _FakeResponse:
+    def __init__(self, payload: dict, status_code: int = 200) -> None:
+        self._payload = payload
+        self.status_code = status_code
+
+    def raise_for_status(self) -> None:
+        if self.status_code >= 400:
+            request = httpx.Request("POST", "http://fake/chat/completions")
+            raise httpx.HTTPStatusError(
+                "error", request=request, response=httpx.Response(self.status_code, request=request)
+            )
+
+    def json(self) -> dict:
+        return self._payload
+
+
+class _FakeAsyncClient:
+    def __init__(self, payload: dict, status_code: int = 200) -> None:
+        self._payload = payload
+        self._status_code = status_code
+
+    async def __aenter__(self) -> "_FakeAsyncClient":
+        return self
+
+    async def __aexit__(self, *args) -> None:
+        return None
+
+    async def post(self, *args, **kwargs) -> _FakeResponse:
+        return _FakeResponse(self._payload, self._status_code)
+
+
+@pytest.mark.asyncio
+async def test_generate_report_strips_thinking_and_returns_content(monkeypatch):
+    payload = {
+        "choices": [
+            {"message": {"content": "<think>hidden</think>## Insights\nBook more direct."}}
+        ]
+    }
+    monkeypatch.setattr(
+        "nf_hotel_api.services.llm_report.httpx.AsyncClient",
+        lambda timeout: _FakeAsyncClient(payload),
+    )
+
+    service = LLMReportService(
+        base_url="http://fake/v1", api_key="k", model="m", timeout_seconds=1.0
+    )
+    report = await service.generate_report({"adults": {"mean": 2}})
+
+    assert report == "## Insights\nBook more direct."
+
+
+@pytest.mark.asyncio
+async def test_generate_report_raises_llm_service_error_on_bad_response(monkeypatch):
+    monkeypatch.setattr(
+        "nf_hotel_api.services.llm_report.httpx.AsyncClient",
+        lambda timeout: _FakeAsyncClient({"unexpected": "shape"}),
+    )
+
+    service = LLMReportService(
+        base_url="http://fake/v1", api_key="k", model="m", timeout_seconds=1.0
+    )
+
+    with pytest.raises(LLMServiceError):
+        await service.generate_report({"adults": {"mean": 2}})