Fix CI JS corruption from obfuscator stdout; clean up flaky test guards

- Strip [javascript-obfuscator-cli] progress line from elc --obfuscate
  output before writing to dist/js/ (was prepended to every compiled JS
  file, causing browser parse errors on stage)
- Remove spurious waitForFunction(signUpWithEmail) guards from
  buyer-name and buyer-email structural tests (pure DOM tests, no auth)
- Switch chat.spec.ts beforeEach to domcontentloaded (SSR elements
  present at DOM ready; networkidle caused cold-start timeouts)

tests/e2e/chat.spec.ts

@@ -7,7 +7,7 @@ import { test, expect } from '@playwright/test';
 test.describe('Demo chat widget — structure', () => {
   test.beforeEach(async ({ page }) => {
     await page.goto('/');
-    await page.waitForLoadState('networkidle');
+    await page.waitForLoadState('domcontentloaded');
   });
 
   test('Demo panel (#neuron-demo-panel) is in the DOM', async ({ page }) => {
@@ -41,7 +41,7 @@ test.describe('Demo chat widget — auth gate', () => {
         .forEach(k => localStorage.removeItem(k));
     });
     await page.reload();
-    await page.waitForLoadState('networkidle');
+    await page.waitForLoadState('domcontentloaded');
   });
 
   test('Send button is disabled when unauthenticated', async ({ page }) => {