Rule off notice chips from the body the way a tagline is

A notice chip -- Msg output, an older message, the leader chord, a prompt --
is a piece of tagline hung over the body's top rows, but in the SDL shell it
ended in a bare edge while the tagline above it ends in a rule. It now has
the tagline's rule along its bottom: the chrome border colour, one pixel,
running on to the window edge when the chip does. A chip still falling into
place brings its rule with it, cut at its row's top like the chip.

The macOS shell already rules every non-workspace tag layer, notices
included; a terminal draws no rule under its tagline, so its chips get none
either.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

1 files changed, 18 insertions, 2 deletions

diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index 989f6b25..92ded62c 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -295,8 +295,9 @@ test "a persistent scene presents a new panel's frame zero before advancing it"
     for (second.panelTracks()) |track| try std.testing.expectEqual(@as(u16, 1), track.frame);
 }
 
-// Per pane: background, rule, two grip strokes, and two square rails.
-const pane_chrome_vertices: usize = 6 * 6;
+// Per pane: background, rule, two grip strokes, two square rails, and the
+// rule under each of its notice chips.
+const pane_chrome_vertices: usize = 6 * (6 + pardes.Pane.Notices.max);
 const max_overlay_vertices: usize = 24 + pet.max_vertices + pardes.MAX_COLS * 6 + pardes.MAX_PANES * pane_chrome_vertices + touch_click_flash_vertices + max_touch_points * (1100 + max_touch_trail_points * overlay_circle_vertices);
 
 const font_px_step: f32 = 2.0;
@@ -7297,6 +7298,21 @@ fn appendPaneChrome(
             appendSquareRail(builder, x0, thumb_y0, thumb_y1, layout.w, true, overlayRgb(chrome.scroll_thumb));
         }
     }
+    // A notice chip is tagline hung over the body's top rows, so it is ruled
+    // off from the text beneath it the way a tagline is: the same colour and
+    // thickness along its bottom, running to the window edge when it does.
+    for (surface.tagLayers()) |*layer| {
+        if (layer.cols == 0 or layer.kind != .notice) continue;
+        const x0 = @as(f32, @floatFromInt(layer.viewport.x)) * layout.w;
+        const x1 = x0 + @as(f32, @floatFromInt(layer.viewport.w)) * layout.w;
+        const rule_x1 = if (builder.win_w - x1 < layout.w) @max(x1, builder.win_w) else x1;
+        const top = @as(f32, @floatFromInt(layer.viewport.y)) * layout.h;
+        // A band still falling into place is cut at its row's top; its rule
+        // comes with it, and shows only once it is below that cut.
+        const rule_y = top + (1 + layer.slide) * layout.h;
+        if (rule_y - 1 < top) continue;
+        builder.addRect(x0, rule_y - 1, rule_x1, rule_y, overlayRgb(chrome.border));
+    }
     appendColumnSpines(core, surface.rows, layout, builder);
 }