Use essential canvas boundaries and outline selected state rows

crates/oa-desktop/src/behavior/scenario_lifecycle/render.rs

@@ -240,9 +240,9 @@ impl Rendering {
                     ..Stroke::default()
                         .with_width(1.)
                         .with_color(if id == selected {
-                            Color::from_rgb8(148, 190, 187)
+                            style::TEAL
                         } else {
-                            Color::from_rgb8(214, 222, 222)
+                            style::BOUNDARY
                         })
                 },
             );
@@ -262,7 +262,7 @@ impl Rendering {
                             if lifetime.lifeline == selected {
                                 style::TEAL
                             } else {
-                                Color::from_rgb8(91, 113, 113)
+                                style::BOUNDARY
                             },
                         ),
                     ),

crates/oa-desktop/src/behavior/state_canvas.rs

@@ -1514,7 +1514,7 @@ fn paint_node(
     }
     for (relation, row) in state_action_rows(project, node) {
         if relation.id == selected {
-            frame.fill_rectangle(row.position(), row.size(), Color::from_rgb8(224, 247, 242));
+            paint_selected_row(frame, row);
         }
         label_text(
             frame,
@@ -1530,7 +1530,7 @@ fn paint_node(
     }
     for (relation, row) in internal_rows(project, node) {
         if relation.id == selected {
-            frame.fill_rectangle(row.position(), row.size(), Color::from_rgb8(224, 247, 242));
+            paint_selected_row(frame, row);
         }
         frame.stroke(
             &line(row.position(), Point::new(row.x + row.width, row.y)),
@@ -1565,6 +1565,22 @@ fn paint_node(
     }
 }
 
+fn paint_selected_row(frame: &mut Frame, row: Rectangle) {
+    frame.fill_rectangle(row.position(), row.size(), Color::from_rgb8(224, 247, 242));
+    if row.width <= 2. || row.height <= 2. {
+        return;
+    }
+    // Selection remains visible without hue. Keep the outline inside the
+    // existing row so it cannot cover its separator or change its hit bounds.
+    frame.stroke(
+        &Path::rectangle(
+            row.position() + Vector::new(1., 1.),
+            Size::new(row.width - 2., row.height - 2.),
+        ),
+        Stroke::default().with_color(style::TEAL).with_width(1.5),
+    );
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;