Refactor flake api package and adjust prod nix config

web-app/playwright.config.ts

@@ -3,10 +3,10 @@ import { type PlaywrightTestConfig, devices } from "@playwright/test";
 const config: PlaywrightTestConfig = {
   webServer: {
     command: "npm run build && npm run preview",
-    url: "http://localhost:4173"
+    url: "http://127.0.0.1:4173"
   },
   use: {
-    baseURL: "http://localhost:4173",
+    baseURL: "http://127.0.0.1:4173",
     video: "retain-on-failure"
   },
   testDir: "./tests",