Added the sqlite3 database

backend/app/main.py

@@ -0,0 +1,25 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.routers import address, contact, proposal, dewar, shipment
+
+app = FastAPI()
+
+# Apply CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # Enable CORS for all origins for now
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include your routers
+app.include_router(contact.router, prefix="/contacts", tags=["contacts"])
+app.include_router(address.router, prefix="/return_addresses", tags=["return_addresses"])
+app.include_router(proposal.router, prefix="/proposals", tags=["proposals"])
+app.include_router(dewar.router, prefix="/dewars", tags=["dewars"])
+app.include_router(shipment.router, prefix="/shipments", tags=["shipments"])
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host="127.0.0.1", port=8000, log_level="debug")