fix: collapse the surface height when the in-surface menu closes

The first live probe caught the surface stuck at menu height after
close: rebuild_layout reset the width but not the height, and the
compositor deliberately stops enforcing size while a segment is thicker
than the bar — so nobody collapsed it. The no-menu path now explicitly
resets height to the bar strip; verified live: open 104x24→190x118,
close →104x24, neighbors frozen, zero configures either way.

Co-Authored-By: Claude Fable 5 <[email protected]>

 src/main.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 73e84f1..6f3d990 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -649,6 +649,14 @@ impl StatusApp {
                 self.input_regions.clear();
                 self.input_regions.push((0, 0, self.width as i32, bar_h.round() as i32));
 
+                // No open menu: the surface is exactly the bar strip. This
+                // reset is what COLLAPSES an expanded surface after the menu
+                // closes — the compositor deliberately stops enforcing size
+                // while we are thicker than the bar, so nobody else will.
+                if self.context_menu.is_none() {
+                    self.height = bar_h.round() as u32;
+                }
+
                 // In-surface context menu: grow the surface below the bar
                 // strip and draw the menu into the retained buffers. The
                 // panel reuses the module box pipeline (so box_bevel applies)