fix: use regex pattern for version check in E2E test

Replace hardcoded version '3.15.0' with regex pattern to match any
semver version, preventing test failures on version updates.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mcollina

web/frontend/test/e2e/basic.spec.ts

@@ -47,7 +47,7 @@ test.describe('Basic E2E tests', () => {
     await expect(page.getByText('composer')).toHaveCount(1)
     await expect(page.getByText('gateway')).toHaveCount(1)
     await expect(page.getByText('RUNNING')).toBeVisible()
-    await expect(page.getByText('3.15.0')).toBeVisible()
+    await expect(page.getByText(/^\d+\.\d+\.\d+$/)).toBeVisible()
     await expect(page.getByText('http://127.0.0.1:5042')).toBeVisible()
 
     const metricCharts = page.getByTestId('metric-chart')