refactor(client): replace remote-object switch with a factory registry

[dgozman]

Summary

• Convert the hand-written switch in Connection._createRemoteObject into a Map<string, ChannelOwnerFactory> populated by registerObjectFactories().
• The Connection constructor seeds the registry with all built-in types, preserving today's behavior.
• Sets up the extension point for plugin-style client modules to register their channel-owner classes from outside playwright-core/client.

No behavior change.

[github-actions]

Test results for "MCP"

4 failed
❌ [firefox] › mcp/http.spec.ts:103 › http transport browser lifecycle (isolated) @mcp-windows-latest-firefox
❌ [firefox] › mcp/http.spec.ts:142 › http transport browser sigint @mcp-windows-latest-firefox
❌ [msedge] › mcp/annotate.spec.ts:273 › should enter annotate mode on fresh dashboard.tsx mount with -s --annotate @mcp-windows-latest-msedge
❌ [msedge] › mcp/annotate.spec.ts:297 › should annotate via direct browser_annotate MCP call @mcp-windows-latest-msedge

6991 passed, 1052 skipped

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Merge workflow run.

[github-actions]

Test results for "tests 1"

Warning

The triggering workflow run ended with status cancelled. Results below may be incomplete — blob reports from cancelled or timed-out shards are missing, so passing/failing counts do not reflect the full test suite.

1 failed
❌ [firefox-page] › page/page-emulate-media.spec.ts:196 › should report hover and fine pointer for desktop @firefox-ubuntu-22.04-node20

4 flaky

⚠️ [installation tests] › playwright-cdn.spec.ts:75 › playwright cdn should not timeout on redirect `@package-installations-windows-latest`
⚠️ [chromium-library] › library/video.spec.ts:719 › screencast › should work with video+trace `@chromium-ubuntu-22.04-arm-node20`
⚠️ [firefox-page] › page/page-emulate-media.spec.ts:144 › should keep reduced motion and color emulation after reload `@firefox-ubuntu-22.04-node20`
⚠️ [playwright-test] › ui-mode-test-output.spec.ts:118 › should collapse repeated console messages for test `@ubuntu-latest-node22`

41587 passed, 851 skipped

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Merge workflow run.