fix(app): inset tab color indicator

packages/app/src/components/titlebar-tab-nav.css

@@ -10,7 +10,17 @@
 }
 
 [data-titlebar-tab][data-tab-color] {
-  box-shadow: inset 0 -1px 0 var(--tab-color);
+  &::after {
+    content: "";
+    position: absolute;
+    right: 8px;
+    bottom: 0;
+    left: 8px;
+    height: 2px;
+    pointer-events: none;
+    border-radius: 2px 2px 0 0;
+    background: var(--tab-color);
+  }
 }
 
 [data-slot="titlebar-tabs"] {