Chat view wastes horizontal space so markdown tables clip and wrap poorly

Short summary

Chat conversation view leaves large unused horizontal space, so markdown tables clip and wrap instead of using the available screen width.

Affected version or release

1.1.17 (github.exe ProductVersion 1.1.17)

Installation context

Windows 11 Enterprise (build 26200), GitHub Copilot desktop app, conversation / chat view.

What happened?

In a conversation, the transcript is constrained to a narrow center column. A large empty gutter sits on the left (and unused space on the right), while the chat content itself is too narrow for multi-column markdown tables.

Result:

• Table columns wrap aggressively and become hard to read
• The last column is clipped / truncated (text cut off mid-word)
• Wide content cannot use the screen space that is already empty

This makes tables, issue lists, and similar structured replies much less usable on a normal desktop window.

Steps to reproduce

1. Open the GitHub Copilot app on a wide desktop window.
2. Open or continue a conversation.
3. Ask the agent for a multi-column markdown table (4+ columns with links and longer sentences).
4. Observe the conversation column staying narrow while large side areas stay empty, and the table clipping or wrapping poorly.

Expected behavior

The conversation view should use more of the available window width. Markdown tables should remain fully readable without clipping the last column or wasting large empty side gutters.

Additional context

Related:

• https://github.com/github/app/issues/3195 (unused horizontal space / narrow center column)
• https://github.com/github/app/issues/3719 (option to increase chat width)
• https://github.com/github/app/issues/3081 (markdown table wrapping / layout)

This report is specifically about conversation rendering: unused side space plus clipped tables on Windows 1.1.17.

Reproduce the issue in the conversation view on a wide Windows desktop window using a multi-column markdown table with long text and links. Trace the conversation layout and rendering entry points, then verify that the view uses more available width and that the table's final column is no longer clipped or excessively wrapped.