finally found how to turn off HMR

src/index.ts

···
 export const app = new Elysia({
 		serve: {
 			maxPayloadLength: 1024 * 1024 * 128 * 3,
+			development: Bun.env.NODE_ENV !== 'production' ? true : false,
+			id: Bun.env.NODE_ENV !== 'production' ? undefined : null,
 		}
 	})
 	// Observability middleware

src/lib/observability.ts

···
 				service
 			)
 
-			logCollector.error(
-				`Request failed: ${request.method} ${url.pathname}`,
-				service,
-				error,
-				{ statusCode: set.status || 500 }
-			)
+			// Don't log 404 errors
+			const statusCode = set.status || 500
+			if (statusCode !== 404) {
+				logCollector.error(
+					`Request failed: ${request.method} ${url.pathname}`,
+					service,
+					error,
+					{ statusCode }
+				)
+			}
 		}
 	}
 }