feat(spa): add loading bar (#1684)

quartz/styles/base.scss

@@ -587,3 +587,14 @@ iframe.pdf {
   width: 100%;
   border-radius: 5px;
 }
+
+.navigation-progress {
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 0;
+  height: 3px;
+  background: var(--secondary);
+  transition: width 0.2s ease;
+  z-index: 9999;
+}