fix(reporter): strip ansi from test stdout when colors are disabled

[pavelfeldman]

Summary

• Wraps the reporter's stdout/stderr with a Writable that strips ANSI escapes when useColors is false (e.g. FORCE_COLOR=0), so user-printed ANSI sequences and reporter cursor codes don't leak into non-color output.

Fixes #40683

[github-actions]

Test results for "MCP"

6 failed
❌ [chrome] › mcp/test-run.spec.ts:126 › test_run should stop when aborted @mcp-windows-latest-chrome
❌ [firefox] › mcp/cli-session.spec.ts:99 › session stops when browser exits @mcp-windows-latest-firefox
❌ [msedge] › mcp/annotate.spec.ts:57 › should capture multiple screenshots in one annotation @mcp-windows-latest-msedge
❌ [msedge] › mcp/annotate.spec.ts:110 › should abort annotation when last screenshot is removed @mcp-windows-latest-msedge
❌ [webkit] › mcp/config.ini.spec.ts:57 › ini config sets browser launch options @mcp-windows-latest-webkit
❌ [webkit] › mcp/config.spec.ts:138 › browser_get_config returns merged config from file, env and cli @mcp-windows-latest-webkit

7009 passed, 1058 skipped

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Merge workflow run.

[github-actions]

Test results for "tests 1"

2 flaky

⚠️ [chromium-library] › library/video.spec.ts:476 › screencast › should capture static page in persistent context @smoke `@chromium-ubuntu-22.04-node22`
⚠️ [playwright-test] › ui-mode-test-output.spec.ts:118 › should collapse repeated console messages for test `@ubuntu-latest-node22`

41658 passed, 851 skipped

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Merge workflow run.