feat(PWAManifest): Use sensible defaults for icons

Defining SVG both as 17x17 and 512x512 is intended to support custom
splash screens, though the documentation is somewhat unclear. This
currently satisfies the Google Lighthouse auditing tool.

inc/Manifest.php

@@ -42,47 +42,32 @@ class Manifest
 
         if (empty($manifest['icons'])) {
             $manifest['icons'] = [];
+            if (file_exists(mediaFN(':wiki:favicon.ico'))) {
+                $url = ml(':wiki:favicon.ico', '', true, '', true);
+                $manifest['icons'][] = [
+                    'src' => $url,
+                    'sizes' => '16x16',
+                ];
+            }
+
             $look = [
-                ':wiki:logo.png',
-                ':logo.png',
-                'images/logo.png',
-                ':wiki:apple-touch-icon.png',
-                ':apple-touch-icon.png',
-                'images/apple-touch-icon.png',
-                ':wiki:favicon.svg',
-                ':favicon.svg',
-                'images/favicon.svg',
-                ':wiki:favicon.ico',
-                ':favicon.ico',
-                'images/favicon.ico',
-                ':wiki:logo',
+                ':wiki:logo.svg',
+                ':logo.svg',
+                ':wiki:dokuwiki.svg'
             ];
 
-            $abs = true;
-            foreach ($look as $img) {
-                if ($img[0] === ':') {
-                    $file = mediaFN($img);
-                    $ismedia = true;
-                } else {
-                    $file = tpl_incdir() . $img;
-                    $ismedia = false;
-                }
-
-                if (file_exists($file)) {
-                    $imginfo = getimagesize($file);
-                    if ($ismedia) {
-                        $url = ml($img, '', true, '', $abs);
-                    } else {
-                        $url = tpl_basedir() . $img;
-                        if ($abs) {
-                            $url = DOKU_URL . substr($url, strlen(DOKU_REL));
-                        }
-                    }
+            foreach ($look as $svgLogo) {
+
+                $svgLogoFN = mediaFN($svgLogo);
+
+                if (file_exists($svgLogoFN)) {
+                    $url = ml($svgLogo, '', true, '', true);
                     $manifest['icons'][] = [
                         'src' => $url,
-                        'sizes' => $imginfo[0] . 'x' . $imginfo[1],
-                        'type' => $imginfo['mime'],
+                        'sizes' => '17x17 512x512',
+                        'type' => 'image/svg+xml',
                     ];
+                    break;
                 };
             }
         }