fix: tree rows and chevrons are cut off by the recessed well's bevel

The tree floor is a recessed well whose wall is carved over the row
quads, but labels and chevron icons paint after the recess with a clip
that ran to the widget's outer edges — content sat on top of the bevel
instead of sliding under it. Inset the text bounds and the chevron clip
by the wall depth so both cut at the wall's inner edge (top unchanged:
the wall there is behind the search/header strip).

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

 src/widget/container/treelist.rs | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/widget/container/treelist.rs b/src/widget/container/treelist.rs
index 8603e90..d87eb3a 100644
--- a/src/widget/container/treelist.rs
+++ b/src/widget/container/treelist.rs
@@ -961,7 +961,22 @@ impl Paint for TreeList {
         let search_h = 26.0;
         let offset_y = search_h + 2.0 * search_margin_y;
         let header_h = 26.0;
-        let list_bounds = Some([self.scroll_box.base.x, self.scroll_box.viewport_y, self.scroll_box.base.x + self.scroll_box.base.w, self.scroll_box.viewport_y + self.scroll_box.viewport_h]);
+        // Labels and chevrons paint over the recessed well's wall (the recess
+        // is shading-only and already drawn), so cut them at the wall's inner
+        // edge — content slides under the bevel instead of sitting on it. The
+        // top stays at the viewport: the wall there is behind the search/header
+        // strip, outside the scroll area.
+        let wall = if crate::layout::control_relief() {
+            crate::layout::bevel_width().min(rect.height * 0.2)
+        } else {
+            0.0
+        };
+        let list_bounds = Some([
+            self.scroll_box.base.x + wall,
+            self.scroll_box.viewport_y,
+            self.scroll_box.base.x + self.scroll_box.base.w - wall,
+            self.scroll_box.viewport_y + self.scroll_box.viewport_h - wall,
+        ]);
         let header_bounds = Some([x, y + offset_y, x + w, y + offset_y + header_h]);
         for (idx, (l, col_max_x)) in self.own_labels().into_iter().enumerate() {
             let mut b = if idx < 3 { header_bounds } else { list_bounds };
@@ -972,17 +987,18 @@ impl Paint for TreeList {
         }
 
         // Section chevrons: image icons in the slot own_labels leaves open,
-        // clipped to the list viewport like the row text.
+        // clipped like the row text — to the list viewport shrunk by the
+        // well wall, so arrows are cut off by the bevel, never drawn on it.
         {
             let (_, tree_font_size) = crate::layout::tree_font_parsed();
             let list_left = self.scroll_box.base.x;
             let list_top = self.scroll_box.viewport_y;
             let list_bottom = list_top + self.scroll_box.viewport_h;
             let viewport = Rect {
-                x: list_left,
+                x: list_left + wall,
                 y: list_top,
-                width: self.scroll_box.base.w,
-                height: self.scroll_box.viewport_h,
+                width: self.scroll_box.base.w - 2.0 * wall,
+                height: self.scroll_box.viewport_h - wall,
             };
             pc.clip(viewport, |pc| {
                 for (i, item) in self.items.iter().enumerate() {