refactor: Add scrollToSection and fix missing functions

- Add scrollToSection() to utils._hs (was missing after cv-functions.js removal)
- Move error toast close handler to inline hyperscript
- Remove initMenuCloseOnClick() - now integrated into scrollToSection()
- Remove initErrorToastClose() - now hyperscript inline handler
- Remove unused initScrollBehaviorJS() fallback (~70 lines dead code)

This fixes the navigation menu scroll functionality and eliminates
more JavaScript in favor of hyperscript.

templates/partials/widgets/error-toast.html

@@ -3,6 +3,7 @@
 <div id="error-toast" class="error-toast no-print" role="alert" aria-live="assertive" style="display: none;">
     <span class="error-icon">⚠️</span>
     <span id="error-message"></span>
-    <button aria-label="Close error message" class="error-close">×</button>
+    <button aria-label="Close error message" class="error-close"
+            _="on click remove .show from #error-toast">×</button>
 </div>
 {{end}}