feat(launchServer): add allowClientNetwork option

[dgozman]

Summary

• Adds allowClientNetwork to BrowserType.launchServer so a connecting client's exposeNetwork can tunnel browser traffic back through the client. The server pre-launches a SocksProxy with the configured pattern and passes it as preLaunchedSocksProxy to PlaywrightServer, reusing the existing SocksSupportDispatcher pipe.

Fixes #31718

[github-actions]

Test results for "MCP"

2 failed
❌ [chrome] › mcp/cli-session.spec.ts:72 › close-all @mcp-macos-latest-chrome
❌ [webkit] › mcp/dashboard.spec.ts:207 › should enter annotate mode on fresh dashboard.tsx mount with -s --annotate @mcp-macos-latest-webkit

6819 passed, 927 skipped

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Merge workflow run.

[github-actions]

Test results for "tests 1"

1 failed
❌ [playwright-test] › ui-mode-test-network-tab.spec.ts:395 › should copy network request @windows-latest-node20

4 flaky

⚠️ [chromium-library] › library/popup.spec.ts:261 › should not throw when click closes popup `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/video.spec.ts:275 › screencast › should capture navigation `@chromium-ubuntu-22.04-node24`
⚠️ [firefox-library] › library/inspector/cli-codegen-1.spec.ts:1080 › cli codegen › should not throw csp directive violation errors `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-wait-for-function.spec.ts:104 › should work with strict CSP policy `@firefox-ubuntu-22.04-node20`

41537 passed, 784 skipped

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Merge workflow run.