feat: implement multilingual support for sitemap and SEO, update structured data, and improve locale middleware configuration

resources/views/layouts/site.blade.php

@@ -17,16 +17,35 @@ $favicon_path = setting('site_favicon');
 		}
 	@endphp
 	@php
-		$seo_canonical = $meta['canonical'] ?? url()->current();
+		$seo_canonical = $meta['canonical'] ?? null;
+		if (!$seo_canonical) {
+			$seo_canonical = url()->current();
+			$localeQuery = request()->query('locale') ?? request()->query('lang');
+			if ($localeQuery && function_exists('available_language_codes') && in_array($localeQuery, available_language_codes())) {
+				$seo_canonical .= '?locale=' . $localeQuery;
+			}
+		}
 		$seo_robots = $meta['robots'] ?? 'index, follow';
 		$seo_og_type = $meta['og_type'] ?? 'website';
 		$seo_og_locale = str_replace('_', '-', $meta['locale'] ?? app()->getLocale());
+
+		$activeLanguages = class_exists(\App\Models\Language::class)
+			? \App\Models\Language::where('is_active', true)->get()
+			: collect([]);
+		$currentUrl = url()->current();
 	@endphp
 	<title>{{ $seo_title }}</title>
 	<meta name="description" content="{{ $seo_description }}">
 	<meta name="robots" content="{{ $seo_robots }}">
 	<link rel="canonical" href="{{ $seo_canonical }}">
 
+	@foreach($activeLanguages as $lang)
+		<link rel="alternate" hreflang="{{ $lang->code }}" href="{{ $currentUrl . '?locale=' . $lang->code }}">
+	@endforeach
+	@if($activeLanguages->count() > 0)
+		<link rel="alternate" hreflang="x-default" href="{{ $currentUrl }}">
+	@endif
+
 	<!-- Open Graph / Facebook -->
 	<meta property="og:type" content="{{ $seo_og_type }}">
 	<meta property="og:url" content="{{ $seo_canonical }}">

resources/views/sitemap.blade.php

@@ -1,8 +1,14 @@
 {!! '<' . '?xml version="1.0" encoding="UTF-8"?' . '>' !!}
-<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
+        xmlns:xhtml="http://www.w3.org/1999/xhtml">
     @foreach($urls as $url)
     <url>
         <loc>{{ $url['loc'] }}</loc>
+        @if(!empty($url['alternates']))
+            @foreach($url['alternates'] as $alt)
+                <xhtml:link rel="alternate" hreflang="{{ $alt['hreflang'] }}" href="{{ $alt['href'] }}"/>
+            @endforeach
+        @endif
         <lastmod>{{ $url['lastmod'] }}</lastmod>
         <changefreq>{{ $url['changefreq'] }}</changefreq>
         <priority>{{ $url['priority'] }}</priority>