[PathGao]

Closes #1076, reported by @chen9986 on macOS Sonoma 14.6.1: the Markpad icon looked larger than the apps next to it.

Mechanism

#841 replaced the icon and rendered icon.icns full-bleed: the dark tile fills the whole 1024px canvas. macOS icons are drawn on a grid where the tile is 824px with a 100px margin, which is what bfe2035 had set up for the old icon. Sonoma draws an .icns as it is, so a full-bleed tile shows about 24% wider than its neighbours. macOS 26 and later mask and inset legacy icons themselves, which is why it only shows on older systems.

icon.icns is now the same artwork scaled into the 824px tile, centred on the 1024px canvas, at every size in the set. The other PNG and ICO icons are unchanged, since Windows and Linux expect full-bleed artwork.

Verification

• Compared the new 1024px image against the current one scaled to 824px: mean absolute difference 0.12 of 255, and the opaque area spans x = 100 to 923.
• Built a test bundle with the new icon. On macOS 27.2 it shows the same size as the current release in Finder and the Dock.
• Not seen on Sonoma or any macOS before 26.