Fix issue #8682: [Bug]: Terminal tab not showing content until page refresh

[openhands-agent]

This pull request fixes #8682.

The issue has been successfully resolved based on the changes made. The core problem was that the terminal wasn't displaying output until page refresh because it was using a persistent reference that prevented proper re-rendering. The specific changes address this by:

1. Replacing the persistent persistentLastCommandIndex with a component-local React.useRef, allowing proper state management per terminal instance
2. Adding terminal.current.reset() when commands change, ensuring the terminal clears properly before re-rendering
3. Modifying the commands effect to re-render ALL commands when the array changes, rather than only rendering new ones
4. Adding proper prompt handling after command rendering

The new test coverage demonstrates that the terminal now correctly re-renders all commands when reinitialized, which directly addresses the original issue of content not displaying until refresh. The changes ensure that command output will display immediately when executed, without requiring a page refresh.

The technical implementation is sound and the changes directly target and fix the reported behavior. The combination of proper terminal reset, complete command re-rendering, and local state management provides a complete solution to the UI bug.

Automatic fix generated by OpenHands 🙌

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:f52a653-nikolaik   --name openhands-app-f52a653   docker.all-hands.dev/all-hands-ai/openhands:f52a653