fix(health): accept HEAD requests for UptimeRobot free tier compatibility

Author: 28nitin07

backend/main.py

@@ -48,7 +48,7 @@ async def lifespan(app: FastAPI):
 app.include_router(router)
 
 
-@app.get("/health")
+@app.api_route("/health", methods=["GET", "HEAD"])
 def health():
     return {"status": "ok", "version": "2.0.0"}