fix(desktop): Settings sidebar redirected to /chats instead of scrolling

App uses HashRouter, so an <a href="#profile"> changes the routing
hash and the router can't find a match — it falls back to /chats.
Replace anchors with buttons that scroll the target section via
scrollIntoView and update the active highlight optimistically.

apps/desktop/src/pages/SettingsPage.tsx

@@ -159,11 +159,23 @@ export function SettingsPage() {
               {sections.map(({ id, label, Icon }) => {
                 const active = activeId === id;
                 return (
-                  <a
+                  // NOTE: must NOT be an `<a href="#id">` — the app uses
+                  // HashRouter where the URL hash IS the route. Anchor links
+                  // would navigate away from /settings instead of scrolling.
+                  // We scroll the section into view programmatically and
+                  // optimistically set activeId so the click feels instant.
+                  <button
                     key={id}
-                    href={'#' + id}
+                    type="button"
+                    onClick={() => {
+                      const el = document.getElementById(id);
+                      if (el) {
+                        el.scrollIntoView({ behavior: 'smooth', block: 'start' });
+                        setActiveId(id);
+                      }
+                    }}
                     className={
-                      'flex cursor-pointer items-center gap-2.5 rounded-lg px-3 py-2 text-sm font-medium transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
+                      'flex w-full cursor-pointer items-center gap-2.5 rounded-lg px-3 py-2 text-left text-sm font-medium transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
                       (active
                         ? 'bg-accent/15 text-fg'
                         : 'text-fg-muted hover:bg-surface-2 hover:text-fg')
@@ -175,7 +187,7 @@ export function SettingsPage() {
                       }
                     />
                     <span className="truncate">{label}</span>
-                  </a>
+                  </button>
                 );
               })}
             </nav>