test(e2e): migrate to Playwright

[aymeric-giraudet]

Summary

• Migrates the main e2e test suite from WebdriverIO to Playwright
• Migrates Next.js package e2e tests (both App Router and Pages Router) from WebdriverIO to Playwright
• Keeps WebdriverIO only for IE11 tests (via Sauce Labs) since Playwright doesn't support IE11
• Updates CircleCI config to run Playwright tests for all e2e jobs except IE11

Changes

• Added Playwright configuration and fixtures with helper methods for InstantSearch interactions
• Rewrote all e2e specs in Playwright syntax
• Updated port from 5000 to 3456 to avoid macOS AirPlay conflict
• Added SPA routing rewrites in website/serve.json for e-commerce examples
• Added .claude/rules/e2e.md documentation for the e2e testing setup

Test plan

• Run yarn website:examples && yarn test:e2e locally
• Verify all Playwright tests pass in CI (Chromium + Firefox)
• Verify IE11 tests still pass via Sauce Labs
• Verify Next.js e2e tests pass for both App Router and Pages Router packages

🤖 Generated with Claude Code

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Latest deployment of this branch, based on commit 9a4c661:

Sandbox	Source
example-instantsearch-getting-started	Configuration
example-react-instantsearch-getting-started	Configuration
example-react-instantsearch-next-app-dir-example	Configuration
example-react-instantsearch-next-routing-example	Configuration
example-vue-instantsearch-getting-started	Configuration

[shaejaz]

looks good!

[Haroenv]

do we still need this? it's deleted in the other package