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/main.py

@@ -0,0 +1,75 @@
+"""
+FastAPI application entry point with CORS configuration
+"""
+import logging
+import os
+
+from fastapi import FastAPI, Request
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.middleware.gzip import GZipMiddleware
+from fastapi.responses import JSONResponse
+
+from logging_config import setup_logging
+from middleware.request_logger import RequestLoggerMiddleware
+from auth.router import router as auth_router
+from auth.service import seed_default_admin
+from routers import risk, alerts, analysis, insights, reports, cases, geocoded, grid
+
+
+setup_logging()
+seed_default_admin()
+
+
+app = FastAPI(
+    title="CBPOA Risk Assessment API",
+    description="API for CBPOA health risk assessment and alert management",
+    version="1.0.0",
+)
+
+app.add_middleware(RequestLoggerMiddleware)
+app.add_middleware(GZipMiddleware, minimum_size=1000)
+
+logger = logging.getLogger("cbpoa.main")
+
+
+@app.exception_handler(Exception)
+async def global_exception_handler(request: Request, exc: Exception):
+    logger.exception("Unhandled exception on %s %s", request.method, request.url.path)
+    return JSONResponse(status_code=500, content={"detail": "Internal server error"})
+
+cors_origins = os.getenv("CORS_ORIGINS", "http://localhost:3000,http://localhost:5173,http://127.0.0.1:3000,http://127.0.0.1:5173").split(",")
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=cors_origins,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+app.include_router(auth_router)
+app.include_router(risk.router)
+app.include_router(alerts.router)
+app.include_router(analysis.router)
+app.include_router(insights.router)
+app.include_router(reports.router)
+app.include_router(cases.router)
+app.include_router(geocoded.router)
+app.include_router(grid.router)
+
+
+@app.get("/")
+async def root():
+    """Root endpoint - API health check"""
+    return {
+        "message": "CBPOA Risk Assessment API",
+        "version": "1.0.0",
+        "status": "running"
+    }
+
+
+@app.get("/health")
+async def health_check():
+    """Health check endpoint for monitoring"""
+    return {"status": "healthy"}