mapsize 1.2.0: permanent delete and in-map reveal when headless

On a headless Linux or BSD system (no DISPLAY or WAYLAND_DISPLAY) nothing
empties the freedesktop trash, so trashing never freed space. There, d now
deletes permanently after an explicit confirmation, checking owner and type
against the scan and removing through an os.Root on the parent so a swapped
symlink cannot redirect it. o shows the folder in the map instead of
launching a file manager. Desktop sessions, macOS and Windows are unchanged.

internal/platform/ops_windows.go

@@ -70,3 +70,9 @@ func Trash(path string, _ Expect) error {
 	}
 	return nil
 }
+
+// Headless is always false: Windows always has Explorer and the Recycle Bin.
+func Headless() bool { return false }
+
+// Delete is not offered on Windows; items go to the Recycle Bin.
+func Delete(string, Expect) error { return errors.New("permanent delete not supported on Windows") }