fix: Use Playwright Docker image for CI to resolve dependency issues

[aoshimash]

Summary

Fix the incomplete implementation of Phase 2 (#63) by using the official Playwright Docker image in CI, which includes all required system dependencies.

Problem

The CI environment (Ubuntu 24.04) was missing critical system dependencies for Playwright:

• GTK4 libraries
• GStreamer libraries
• Various multimedia codecs
• And many more

The playwright install --with-deps chromium command was insufficient due to package naming changes in Ubuntu 24.04 (many packages now have a t64 suffix).

Solution

Use the official Playwright Docker image (mcr.microsoft.com/playwright:v1.48.0-noble) which:

• Has all system dependencies pre-installed
• Is maintained by the Playwright team
• Provides a consistent environment across CI runs
• Eliminates dependency management complexity

Changes Made

1. Added Docker container configuration to CI workflow
2. Removed manual browser installation steps (already in Docker image)
3. Set PLAYWRIGHT_BROWSERS_PATH environment variable
4. Kept Playwright CLI installation for Go integration

Testing

This PR will validate that:

• All tests pass in the Docker container
• Playwright tests can run without dependency errors
• CI performance remains acceptable

Related Issues

• Fixes fix: Install missing system dependencies for Playwright in CI - Phase 2 Fix #68
• Enables completion of feat: Enable all Playwright tests and improve error handling - Phase 3 #64 (Phase 3)
• Related PR: feat: Enable all Playwright tests and improve error handling - Phase 3 #67

🤖 Generated with Claude Code

[aoshimash]

✅ CI成功！

すべてのCIチェックが成功しました。Playwright Dockerイメージを使用することで、依存関係の問題が解決されました。

実装内容

1. Playwright公式Dockerイメージを使用（mcr.microsoft.com/playwright:v1.48.0-noble）
2. CGO有効化とビルドツールのインストール（gcc, g++, libc6-dev）
3. Git所有権の問題を修正
4. 環境変数でプリインストールされたブラウザを使用

結果

• ✅ Test (Go 1.23): 3m24s
• ✅ Test (Go 1.24): 2m51s
• ✅ Build: 25s
• ✅ Test: 38s

これでPhase 2が完了し、CI環境でPlaywrightテストを実行できるようになりました。次はPR #67に戻ってPhase 3を完了できます。