PHLEGM v8 checkpoint 66 - Up/Back folder with two-dot cutout
- Windows icon view: the Up/Back tile is the existing trapezoidal folder
  with two high-contrast white round cutout dots (..); previous arrow removed.
- Linux icon view: the Up button displays the same two-dot folder; the
  folder glyph is rendered once via icons.lib and cached with icon kind 8.
- Normal folder and ZIP icon silhouettes, cutout badges and console prompt
  icon remain unchanged.
- Tree/Icons hierarchy position preservation from checkpoint 65 remains.
- Static inspection/ZIP validation only: no native FreeBASIC build performed.
