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_report_service.py

@@ -0,0 +1,28 @@
+import pytest
+
+from nf_hotel_api.repositories.booking_repository import JsonBookingRepository
+from nf_hotel_api.services.cleaning import DataCleaningService
+from nf_hotel_api.services.report import ReportService
+from nf_hotel_api.services.statistics import DescriptiveStatsService
+
+
+class _FakeLLMService:
+    async def generate_report(self, descriptive_stats: dict) -> str:
+        assert "booking_id" not in descriptive_stats
+        return "## Fake Report"
+
+
+@pytest.mark.asyncio
+async def test_generate_produces_stats_and_llm_report(dirty_bookings_df, hotel_metadata):
+    repository = JsonBookingRepository(dirty_bookings_df.to_dict(orient="records"))
+    service = ReportService(
+        cleaning_service=DataCleaningService(hotel_metadata),
+        stats_service=DescriptiveStatsService(),
+        llm_service=_FakeLLMService(),
+    )
+
+    result = await service.generate(repository)
+
+    assert result.llm_report == "## Fake Report"
+    assert "adults" in result.descriptive_stats
+    assert "booking_id" not in result.descriptive_stats