SEO fixes: robots.txt, canonicals, noindex, og tags, breadcrumbs, similar games, review schema

- robots.txt: proper Disallow rules + sitemap URL
- Layout: robots meta tag, fix canonical syntax, og:site_name, full Twitter Card tags
- Game pages: canonical URLs, og:type website, breadcrumb nav + JSON-LD schema
- Screenshot alt text with game title and index
- VideoGame JSON-LD: review array with rating/author/body
- Similar Games section on game detail (by genre, ordered by rating)
- browse/index: noindex on paginated or multi-filter pages
- search results: noindex + improved title
- User library and lists: noindex
- Unique meta descriptions on browse, top-rated, new-releases pages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

resources/views/layouts/app.blade.php

@@ -4,9 +4,10 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <meta name="csrf-token" content="{{ csrf_token() }}">
+    <meta name="robots" content="@yield('robots', 'index,follow')">
     <title>@yield('title', 'GameLog — Track Every Game You Play')</title>
     <meta name="description" content="@yield('description', 'GameLog lets you track every game you play, rate your favorites, and discover what to play next.')">
-    @hasSection('canonical')
+    @if(View::hasSection('canonical'))
     <link rel="canonical" href="@yield('canonical')">
     @endif
 
@@ -16,7 +17,11 @@
     <meta property="og:image" content="@yield('og_image', asset('images/og-default.jpg'))">
     <meta property="og:type" content="@yield('og_type', 'website')">
     <meta property="og:url" content="@yield('og_url', url()->current())">
+    <meta property="og:site_name" content="GameLog">
     <meta name="twitter:card" content="summary_large_image">
+    <meta name="twitter:title" content="@yield('title', 'GameLog — Track Every Game You Play')">
+    <meta name="twitter:description" content="@yield('description', 'GameLog lets you track every game you play, rate your favorites, and discover what to play next.')">
+    <meta name="twitter:image" content="@yield('og_image', asset('images/og-default.jpg'))">
 
     <!-- Fonts -->
     <link rel="preconnect" href="https://fonts.bunny.net">