Close Docker log streams when consumers stop reading

[0xTinker]

Summary

• close the demuxed log stream when a consumer closes the public log stream
• cover the stream ownership chain with a regression test

This lets Bun exit after Ryuk’s log wait completes. The change is non-breaking: it only releases the underlying Docker follow stream after the caller has already closed the returned stream.

Verification

• focused test failed before the fix and passed after it
• npm run format
• npm run lint
• npm run check-compiles
• Bun 1.3.14 reproduction exits naturally

Closes #1431

[netlify]

✅ Deploy Preview for testcontainers-node ready!

Name	Link
🔨 Latest commit	68c8cd5
🔍 Latest deploy log	https://app.netlify.com/projects/testcontainers-node/deploys/6a7841aa7ff15f0008338d32
😎 Deploy Preview	https://deploy-preview-1432--testcontainers-node.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.