feat: Introduce the new Shaarli-pro theme with its templates, styles, and scripts.

shaarli-pro/includes.html

@@ -6,9 +6,25 @@
 <link rel="alternate" type="application/atom+xml" href="{$feedurl}?do=atom{$searchcrits}#" title="ATOM Feed" />
 <link rel="search" type="application/opensearchdescription+xml" href="{$base_path}/open-search#" title="Shaarli search - {$shaarlititle}" />
 
+<!-- Prevent dark mode flash (FOUC) - must run before CSS loads -->
+<script>
+(function() {
+    var t = localStorage.getItem('theme') ||
+        (window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light');
+    if (t === 'dark') {
+        document.documentElement.setAttribute('data-theme', 'dark');
+        document.addEventListener('DOMContentLoaded', function() {
+            var mc = document.querySelector('meta[name="theme-color"]');
+            if (mc) mc.setAttribute('content', '#1e293b');
+        });
+    }
+})();
+</script>
+
 <!-- Professional Theme CSS -->
 <link type="text/css" rel="stylesheet" href="{$asset_path}/css/style.css#" />
 
+
 <!-- Icons (Material Design Icons) -->
 <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/MaterialDesign-Webfont/7.2.96/css/materialdesignicons.min.css">