Add Playwright E2E testing with recorded workflows

- Add @playwright/test as dev dependency
- Create playwright.config.ts with Chrome-only testing config
- Add npm scripts: test:record, test:e2e, test:replay
- Create 13 test recordings covering:
  - 2-player and 3-player games
  - 8-ball, 9-ball, and 10-ball game types
  - Various race-to values (1, 3, 5, 7, 9) and "endlos" mode
  - Both wechselbreak (alternating) and winnerbreak rules
- Fix Infinity handling in gameService.ts and NewGameScreen.tsx
  - Parse "endlos" and "Infinity" strings as Infinity number
  - Properly serialize Infinity as string in form data
- Increase GameDetail score font size from 20vh to 40vh
- Update README.md with testing documentation:
  - Quick start guide for recording and running tests
  - Move E2E testing from "Future Improvements" (now implemented)
- Add comprehensive tests/recordings/README.md documentation

Purpose: Establishes browser automation testing infrastructure with
real workflow recordings, enabling regression testing and interaction
documentation for all game configuration combinations.

README.md

@@ -77,8 +77,42 @@ npm run dev
 npm run dev      # Start development server
 npm run build    # Build for production
 npm run preview  # Preview production build
+npm run test:record  # Record browser interactions with Playwright
+npm run test:e2e    # Run all recorded browser automation scripts
 ```
 
+## 🧪 Testing
+
+The project uses **Playwright** for browser automation and recording. This allows you to record interactions once and replay them anytime, making it easy to test repetitive workflows.
+
+### Quick Start
+
+**Recording interactions:**
+```bash
+# Terminal 1: Start dev server
+npm run dev
+
+# Terminal 2: Start recording
+npm run test:record
+```
+
+**Running recordings:**
+```bash
+npm run test:e2e
+```
+
+### Features
+
+- **Record interactions**: Use Playwright codegen to capture clicks, form fills, and navigation
+- **Replay scripts**: Run recorded scripts automatically
+- **Duplicate & modify**: Copy any script and modify it (e.g., change the last step from clicking 'z' to clicking 'a')
+- **Full scripting power**: Edit generated TypeScript files directly for custom automation
+
+### Documentation
+
+For detailed instructions on recording, modifying, and running scripts, see:
+- **[tests/recordings/README.md](tests/recordings/README.md)** - Complete workflow documentation
+
 ## 📁 Project Structure
 
 ### **Core Components**
@@ -199,8 +233,7 @@ The application includes PWA features:
 
 ## 📈 Future Improvements
 
-- Unit and integration testing with Vitest
-- E2E testing with Playwright
+- Unit and integration testing (if needed)
 - Internationalization (i18n) support
 - Advanced game statistics and analytics
 - Real-time multiplayer support