git_graph: Make canvas column resizeable

[feeiyu]

Make git graph canvas column resizeable

2026-03-05.09-46-10.webm

Before you mark this PR as ready for review, make sure that you have:

• Added a solid test coverage and/or screenshots from doing manual testing
• Done a self-review taking into account security and performance aspects
• Aligned any UI changes with the UI checklist

Release Notes:

• N/A

[RemcoSmitsDev]

Great work, I think one thing that is not inline with the other part of the table is that the border is not blue when you are dragging. We didn't do that for the commit view as it feels more like a panel then a column in the table, so its inline with other parts of the editor's UI.

[feeiyu]

Thanks for pointing that out!

In other parts of the table, the border turns blue on hover, not while dragging. I’ve updated the behavior to keep it consistent.

[Anthony-Eid]

I'm closing this because it's not compatible with the table's resize handles, which makes the resize between the graph canvas column and the other columns behave strangely.