nav: add a Learn tab pointing at the teaching site, and drop the scroll-spy underline - tracking the active section as you scrolled read as clunky, so the underline is hover-only now; also refresh the public CV

src/components/Nav.astro

@@ -2,16 +2,15 @@
 import ThemeToggle from "./ThemeToggle.astro";
 import { site } from "../data/site";
 
-// `id` ties a nav link to a homepage section so the Motion layer animates its
-// underline as that section scrolls through (scroll-spy). Projects/Blog navigate
-// to their own pages on click, but on the homepage they track the #projects and
-// #writing sections so every nav item gets the underline - in both directions.
+// Plain links. Hover shows the underline; there is no scroll-spy - tracking the
+// active section as you scrolled read as clunky, so the underline is hover-only.
 const links = [
-  { label: "About", href: "/#about", id: "about" },
-  { label: "Skills", href: "/#skills", id: "skills" },
-  { label: "Projects", href: "/projects/", id: "projects" },
-  { label: "Blog", href: "/blog/", id: "writing" },
-  { label: "Contact", href: "/#contact", id: "contact" },
+  { label: "About", href: "/#about" },
+  { label: "Skills", href: "/#skills" },
+  { label: "Projects", href: "/projects/" },
+  { label: "Blog", href: "/blog/" },
+  { label: "Contact", href: "/#contact" },
+  { label: "Learn", href: "https://learn.bztmon.com", external: true },
 ];
 ---
 
@@ -23,7 +22,11 @@ const links = [
 
     <nav class="nav__links" aria-label="Primary">
       {links.map((l) => (
-        <a href={l.href} data-nav-id={l.id}>
+        <a
+          href={l.href}
+          target={l.external ? "_blank" : undefined}
+          rel={l.external ? "noopener noreferrer" : undefined}
+        >
           {l.label}<span class="nav__ul" aria-hidden="true"></span>
         </a>
       ))}
@@ -95,8 +98,9 @@ const links = [
     color: var(--text);
     text-decoration: none;
   }
-  /* Active-section / hover underline - scaleX scrubbed by the Motion layer
-     (spring). transform-origin left so it grows from the start of the label. */
+  /* Hover underline - scaleX sprung by the Motion layer, growing from the
+     start of the label. No scroll-spy: it tracked the active section as you
+     scrolled, which read as clunky on a page this short. */
   .nav__ul {
     position: absolute;
     left: 0;