fix: tighten secondary-nav cluster left edge

Strips padding-left from the first .nav-link in SecondaryNavLinks so
the cluster sits flush against neighboring widgets in desktopRight
(e.g. the notifications bell). Inter-link padding within the cluster
is preserved.

Refs #245

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: brian-smith-tcril

shell/header/app.scss

@@ -11,4 +11,10 @@ header {
       color: var(--pgn-color-active, #fff);
     }
   }
+
+  // Secondary-nav cluster sits flush against whatever's to its left
+  // (notifications bell, etc.) — those neighbors bring their own padding.
+  .secondary-nav-links > :first-child {
+    padding-left: 0;
+  }
 }

shell/header/desktop/SecondaryNavLinks.tsx

@@ -3,7 +3,7 @@ import { Slot } from '../../../runtime';
 
 export default function SecondaryNavLinks() {
   return (
-    <Nav className="flex-nowrap">
+    <Nav className="flex-nowrap secondary-nav-links">
       <Slot id="org.openedx.frontend.slot.header.secondaryLinks.v1" />
     </Nav>
   );