Add initial implementation of CalMiner with project structure, environment setup, and core features

- Create .env.example for environment variables
- Update README with project structure and development setup instructions
- Implement FastAPI application with API routes for scenarios and parameters
- Add database models for scenarios, parameters, and simulation results
- Introduce validation middleware for JSON requests
- Create services for running simulations and generating reports
- Add testing strategy and directory structure in documentation

main.py

@@ -0,0 +1,17 @@
+from routes.parameters import router as parameters_router
+from fastapi import FastAPI
+from fastapi.middleware import Middleware
+from middleware.validation import validate_json
+from config.database import Base, engine
+from routes.scenarios import router as scenarios_router
+
+# Initialize database schema
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI()
+# Register validation middleware
+app.middleware("http")(validate_json)
+
+# Include API routers
+app.include_router(scenarios_router)
+app.include_router(parameters_router)