[WIP] [FR] Improve scrolling during drag and drop

[Claude]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[FR] Improved Scrolling while Drag and Dropping</issue_title>
<issue_description>Helping you test the drag and drop thing, I created a column of every type, and on my normal-width monitor, I quickly realized it wasn't naturally panning to the left/right when I drag the card to the side. Not at any significant/workable capacity for a wide board. To work around, I ended up continually popping into the settings to rearrange the board columns and then refresh the board (for the bug where the contents of the column are incorrect until refreshing).

Expected behavior, when dragging a card close to the edge (probably extending X% off the side of the screen/window or however you code it), then the board would start panning that direction so the drag and drop experience is better. At present the board does pan itself, but the percentage of edges are very small. We will need to drag and hold our mouse precisely at the edge of the board so that it can start panning. Requesting to increase this percentage of the side edges so the panning starts faster. This project right now uses the native drag and drop functionality/API of HTML5, so not sure what will be the better way to implement this.</issue_description>

Comments on the Issue (you are @claude[agent] in this section)

• Fixes [FR] Improved Scrolling while Drag and Dropping #683