W10: Disk space percentage in status line

Show the free-space percentage next to the disk indicator dot
so the user can quickly assess remaining capacity without doing
mental math from the size string.

Tests: 1388 pass, zero warnings.

local/recipes/tui/tlc/source/src/terminal/status.rs

@@ -268,7 +268,7 @@ impl StatusLine {
                 };
                 let free_str = format_size_short(free);
                 right_spans.push(Span::styled(
-                    format!(" \u{25cf}{free_str} "),
+                    format!(" \u{25cf}{free_str} {pct_free}% "),
                     Style::default().fg(disk_color).bg(effective_bg),
                 ));
             }