adding a left sidebar for article summary. changed right sidebar behavior between homepage and in-articles

php/sidebar.php

@@ -20,10 +20,10 @@
 	<?php
 		// Plugins are rendered in a fixed order (see index.php):
 		//   Blog/About > Search > Navigation > Category > … > Hit Counter (bottom)
-		// On the homepage front page the search box is shown under the hero, so
-		// it is omitted from the sidebar there.
-		if ($heroVisible) {
-			echo $sidebarNoSearchHtml;
+		// On the homepage the navigation is redundant (posts are already listed),
+		// and the search box lives under the hero, so show only about/categories/counters.
+		if ($WHERE_AM_I === 'home') {
+			echo $sidebarHomeHtml;
 		} else {
 			echo $sidebarFullHtml;
 		}

php/toc.php

@@ -0,0 +1,6 @@
+<aside class="toc-sidebar">
+	<div class="toc-title">On this page</div>
+	<nav id="toc-nav" aria-label="Table of contents">
+		<!-- Filled by the ToC script in index.php -->
+	</nav>
+</aside>