Make command output panel expandable in message view

[kripper]

Description:

https://openhands-ai.slack.com/archives/C06QT0AGY4W/p1781643827915699

Command outputs are currently only easy to inspect via the terminal, which makes reviewing older results slow and context-poor. Searching in the terminal is inefficient when trying to trace outputs back to the originating message.

Proposal:

Allow the existing command output panel in the message view to be expanded/collapsed to show full output inline.

Problem:

• Terminal-based inspection is slow for older outputs
• Poor linkage between output and originating message
• Limited context compared to message view

Benefit:

• Faster review of outputs in context
• Easier navigation and debugging
• Reduced reliance on terminal search

[jamiechicago312]

Great issue for new contributors! 🎉

Why this is a good first issue:
This is a small, UI-focused enhancement with a clear user problem and a bounded surface area. The existing chat event cards already support expand/collapse behavior, so this issue is mostly about improving how command output is shown rather than inventing a brand new pattern.

Instructions for tackling this issue:
Start by tracing how terminal/command observations are rendered in the chat stream. Good places to begin are src/components/conversation-events/chat/event-content-helpers/get-observation-content.ts, src/components/conversation-events/chat/event-message-components/generic-event-message-wrapper.tsx, and src/components/features/chat/generic-event-message.tsx. The current behavior is likely limited by how terminal observation content is formatted/truncated before it reaches the expandable card. Add or update focused tests around chat event rendering — __tests__/components/conversation-events/chat/event-message-acp-tool-call.test.tsx is a good pattern for expandable event cards. If you introduce any new user-facing copy, route it through i18n rather than adding raw strings.

Getting started:
You can work on this issue without asking for it to be assigned to you. Feel free to open a pull request directly!

Need help?
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This comment was created by an AI agent (OpenHands) on behalf of the user.