feat: Initial CBPOA commit — 武汉儿童呼吸疾病风险评估系统

Context: Build a spatial risk assessment system correlating air quality
data with children's respiratory disease incidence across Wuhan.

Approach: FastAPI backend serving PostGIS spatial queries, React
frontend with Deck.gl maps, and a PyTorch SpatialTemporalGCN pipeline
for multi-day (1d/3d/7d) risk prediction.

Changes:
- backend/ — FastAPI API with auth (JWT), alerts, risk analysis,
  geocoded case data, grid statistics, and report endpoints
- frontend/ — React dashboard with interactive risk maps, alert
  monitoring, district comparison charts, and timeline player
- models/ — SpatialTemporalGCN model with trained weights and ONNX
  export for inference
- scripts/ — ETL pipeline for weather + medical data, grid generation,
  feature engineering, training, and daily inference
- deploy/ — Docker Compose configs for backend, frontend, and MLflow
- docs/ — API docs, deployment guide, user guide, and code review

Impact: Enables spatial risk visualization, alert monitoring, and
ML-driven health risk forecasting for environmental health teams.

backend/CLAUDE.md

@@ -0,0 +1,41 @@
+# Backend — FastAPI + PostGIS
+
+## Stack
+
+- FastAPI (async), asyncpg connection pool, Pydantic v2 settings
+- PostGIS via GeoAlchemy2, spatial queries with Shapely
+- Auth: python-jose + passlib (JWT/bcrypt)
+
+## Structure
+
+```
+backend/
+  main.py          # App entry, CORS, router registration
+  database.py      # asyncpg pool, Settings from .env
+  models.py         # Pydantic response/request models
+  routers/          # One file per domain (risk, alerts, cases, grid, etc.)
+  app/              # Legacy code (routers/cases.py, routers/grid.py, performance.py)
+```
+
+## Patterns
+
+- Routers: `APIRouter()` with prefix, registered in `main.py` via `app.include_router()`
+- DB access: `async with db.get_connection()` context manager (global `db` singleton)
+- Settings: `pydantic_settings.BaseSettings` loaded from `.env` at module level
+- Endpoints return Pydantic models, not raw dicts
+
+## Running
+
+```bash
+cd backend
+source venv/bin/activate
+uvicorn main:app --reload --port 8000
+```
+
+## Anti-Patterns
+
+- Don't use sync database drivers — always asyncpg
+- Don't put business logic in routers — delegate to service functions
+- Don't hardcode DB credentials — use Settings from environment
+- Don't skip Pydantic validation on request/response bodies
+- Don't import from `app/` — it's legacy, prefer top-level modules