fixes

playwright.config.ts

@@ -2,10 +2,13 @@ import { defineConfig, devices } from '@playwright/test';
 
 export default defineConfig({
   testDir: './e2e',
-  fullyParallel: true,
+  // These tests share a single stateful test server with one fixed dataset and
+  // mutate the same transactions (coding, bulk coding, etc.), so they must run
+  // serially. Running them in parallel causes cross-test races and flakes.
+  fullyParallel: false,
   forbidOnly: !!process.env.CI,
   retries: process.env.CI ? 2 : 0,
-  workers: process.env.CI ? 1 : undefined,
+  workers: 1,
   reporter: 'html',
   use: {
     baseURL: 'http://localhost:3333',