Allow reordering non-name table columns

[lyc280705]

What changed

• allow Type, Size, Modified, and Location columns to be freely reordered
• keep the Name column fixed at the leading edge
• restore the Name column after a non-name column is dropped at index zero

Root cause

AppKit first calls tableView(_:shouldReorderColumn:toColumn:) with a target index of -1 when a drag begins. The previous destination-index check returned false at that stage, which disabled the entire drag.

Validation

• confirmed the documented initial -1 callback behavior in Apple's NSTableViewDelegate documentation
• built the universal app and Finder service locally
• checked the focused source diff and whitespace