feat(seo): complete OG/Twitter/structured-data coverage + clean encoding

Blog list (/blog): add robots, full Open Graph + Twitter, Blog +
BreadcrumbList JSON-LD, per-page self-canonical, and rel=prev/next for
paginated pages.

Blog post: add robots, og:site_name, article:published_time /
modified_time / author / section, twitter:image, og:image:alt, and a
BreadcrumbList JSON-LD (Home → Blog → Category → Post).

Gallery (/gallery): add robots, full OG + Twitter (with first image as
og:image), ImageGallery + BreadcrumbList JSON-LD.

Encoding: register HtmlEncoder.Create(UnicodeRanges.All) so Persian text
in meta tags and JSON-LD renders literally instead of &#xXXXX; entities
(smaller, cleaner output; friendlier to SEO validators).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

DrSousan.Api/Pages/Blog/Index.cshtml

@@ -1,10 +1,58 @@
 @page "/blog"
 @model DrSousan.Api.Pages.Blog.BlogIndexModel
+@{
+    var blogBase   = Environment.GetEnvironmentVariable("SITE_BASE_URL")?.TrimEnd('/') ?? (Request.Scheme + "://" + Request.Host);
+    var catQs      = string.IsNullOrEmpty(Model.ActiveCat) ? "" : "&category=" + Model.ActiveCat;
+    string PageUrl(int p) => p <= 1
+        ? blogBase + "/blog" + (string.IsNullOrEmpty(Model.ActiveCat) ? "" : "?category=" + Model.ActiveCat)
+        : blogBase + "/blog?pg=" + p + catQs;
+    var blogDesc   = "مقالات تخصصی دکتر سوسن آل‌طه درباره زیبایی پوست، بوتاکس، فیلر، لیزر و مراقبت از پوست.";
+}
 
 @section Head {
     <title>@ViewData["Title"]</title>
-    <meta name="description" content="مقالات تخصصی دکتر سوسن آل‌طه درباره زیبایی پوست، بوتاکس، فیلر، لیزر و مراقبت از پوست." />
+    <meta name="description" content="@blogDesc" />
-    <link rel="canonical" href="@((Environment.GetEnvironmentVariable("SITE_BASE_URL")?.TrimEnd('/') ?? (Request.Scheme + "://" + Request.Host)) + "/blog")" />
+    <meta name="robots" content="index, follow, max-image-preview:large, max-snippet:-1" />
+    <meta name="author" content="@ViewData["SiteName"]" />
+    <meta name="theme-color" content="#B8955A" />
+    <link rel="canonical" href="@PageUrl(Model.CurrentPage)" />
+    @if (Model.CurrentPage > 1) { <link rel="prev" href="@PageUrl(Model.CurrentPage - 1)" /> }
+    @if (Model.CurrentPage < Model.TotalPages) { <link rel="next" href="@PageUrl(Model.CurrentPage + 1)" /> }
+
+    <!-- Open Graph -->
+    <meta property="og:type"        content="website" />
+    <meta property="og:site_name"   content="@ViewData["SiteName"]" />
+    <meta property="og:title"       content="@ViewData["Title"]" />
+    <meta property="og:description" content="@blogDesc" />
+    <meta property="og:url"         content="@PageUrl(Model.CurrentPage)" />
+    <meta property="og:locale"      content="fa_IR" />
+    <!-- Twitter -->
+    <meta name="twitter:card"        content="summary" />
+    <meta name="twitter:title"       content="@ViewData["Title"]" />
+    <meta name="twitter:description" content="@blogDesc" />
+
+    <!-- Structured data: Blog + breadcrumb -->
+    <script type="application/ld+json">
+    {
+      "@@context": "https://schema.org",
+      "@@type": "Blog",
+      "name": "@ViewData["Title"]",
+      "description": "@blogDesc",
+      "url": "@(blogBase)/blog",
+      "inLanguage": "fa-IR",
+      "publisher": { "@@type": "Organization", "name": "@ViewData["SiteName"]", "url": "@blogBase" }
+    }
+    </script>
+    <script type="application/ld+json">
+    {
+      "@@context": "https://schema.org",
+      "@@type": "BreadcrumbList",
+      "itemListElement": [
+        { "@@type": "ListItem", "position": 1, "name": "خانه", "item": "@blogBase/" },
+        { "@@type": "ListItem", "position": 2, "name": "وبلاگ", "item": "@blogBase/blog" }
+      ]
+    }
+    </script>
     <style>
       /* ─── Blog Hero ─────────────────────────────────────────────── */
       .blog-hero{background:linear-gradient(135deg,var(--gold-pale) 0%,#EDE0CA 100%);padding:6rem 2rem 3rem;text-align:center}

DrSousan.Api/Pages/Blog/Post.cshtml

@@ -18,17 +18,28 @@
     @if (!string.IsNullOrEmpty(ViewData["Keywords"]?.ToString())) {
         <meta name="keywords" content="@ViewData["Keywords"]" />
     }
+    <meta name="robots" content="index, follow, max-image-preview:large, max-snippet:-1" />
+    <meta name="author" content="@post.Author" />
     <meta property="og:type"        content="article" />
+    <meta property="og:site_name"   content="@ViewData["SiteName"]" />
     <meta property="og:title"       content="@ViewData["Title"]" />
     <meta property="og:description" content="@ViewData["MetaDesc"]" />
     <meta property="og:url"         content="@canonicalUrl" />
     <meta property="og:locale"      content="fa_IR" />
+    @if (!string.IsNullOrEmpty(pubDate)) { <meta property="article:published_time" content="@pubDate" /> }
+    <meta property="article:modified_time" content="@updDate" />
+    <meta property="article:author" content="@post.Author" />
+    @if (post.Category != null) { <meta property="article:section" content="@post.Category.Name" /> }
     @if (!string.IsNullOrEmpty(ogImage)) {
-        <meta property="og:image" content="@(ogImage.StartsWith("http") ? ogImage : baseUrl + ogImage)" />
+        <meta property="og:image"     content="@(ogImage.StartsWith("http") ? ogImage : baseUrl + ogImage)" />
+        <meta property="og:image:alt" content="@post.Title" />
     }
     <meta name="twitter:card"        content="summary_large_image" />
     <meta name="twitter:title"       content="@ViewData["Title"]" />
     <meta name="twitter:description" content="@ViewData["MetaDesc"]" />
+    @if (!string.IsNullOrEmpty(ogImage)) {
+        <meta name="twitter:image" content="@(ogImage.StartsWith("http") ? ogImage : baseUrl + ogImage)" />
+    }
     <link rel="canonical" href="@canonicalUrl" />
 
     <script type="application/ld+json">
@@ -52,6 +63,24 @@
     }
     </script>
 
+    <script type="application/ld+json">
+    {
+      "@@context": "https://schema.org",
+      "@@type": "BreadcrumbList",
+      "itemListElement": [
+        { "@@type": "ListItem", "position": 1, "name": "خانه", "item": "@baseUrl/" },
+        { "@@type": "ListItem", "position": 2, "name": "وبلاگ", "item": "@baseUrl/blog" }@(post.Category != null ? "," : "")
+        @if (post.Category != null) {
+            @:{ "@@type": "ListItem", "position": 3, "name": "@J(post.Category.Name)", "item": "@baseUrl/blog?category=@post.Category.Slug" },
+            @:{ "@@type": "ListItem", "position": 4, "name": "@J(post.Title)", "item": "@canonicalUrl" }
+        }
+        else {
+            @:{ "@@type": "ListItem", "position": 3, "name": "@J(post.Title)", "item": "@canonicalUrl" }
+        }
+      ]
+    }
+    </script>
+
     <style>
       /* ─── Post Layout ──────────────────────────────────────────────── */
       .post-layout{max-width:1100px;margin:0 auto;padding:5rem 2rem 3rem;display:grid;grid-template-columns:1fr 320px;gap:3rem;align-items:start}

DrSousan.Api/Pages/Gallery.cshtml

@@ -1,10 +1,62 @@
 @page "/gallery"
 @model DrSousan.Api.Pages.GalleryModel
+@{
+    var galBase = Environment.GetEnvironmentVariable("SITE_BASE_URL")?.TrimEnd('/') ?? (Request.Scheme + "://" + Request.Host);
+    var galUrl  = galBase + "/gallery";
+    var galDesc = "گالری نتایج واقعی قبل و بعد درمان‌های زیبایی پوست دکتر سوسن آل‌طه — بوتاکس، فیلر، لیزر، مزوتراپی و پاکسازی پوست.";
+    var firstImg = Model.Items
+        .Select(i => !string.IsNullOrEmpty(i.BeforeImageUrl) ? i.BeforeImageUrl : i.ImageUrl)
+        .FirstOrDefault(u => !string.IsNullOrEmpty(u)) ?? "";
+    var absFirstImg = string.IsNullOrEmpty(firstImg) ? "" : (firstImg.StartsWith("http") ? firstImg : galBase + firstImg);
+}
 
 @section Head {
     <title>@ViewData["Title"]</title>
-    <meta name="description" content="گالری نتایج واقعی قبل و بعد درمان‌های زیبایی پوست دکتر سوسن آل‌طه — بوتاکس، فیلر، لیزر، مزوتراپی و پاکسازی پوست." />
+    <meta name="description" content="@galDesc" />
-    <link rel="canonical" href="@((Environment.GetEnvironmentVariable("SITE_BASE_URL")?.TrimEnd('/') ?? (Request.Scheme + "://" + Request.Host)) + "/gallery")" />
+    <meta name="robots" content="index, follow, max-image-preview:large, max-snippet:-1" />
+    <meta name="author" content="@ViewData["SiteName"]" />
+    <meta name="theme-color" content="#B8955A" />
+    <link rel="canonical" href="@galUrl" />
+
+    <!-- Open Graph -->
+    <meta property="og:type"        content="website" />
+    <meta property="og:site_name"   content="@ViewData["SiteName"]" />
+    <meta property="og:title"       content="@ViewData["Title"]" />
+    <meta property="og:description" content="@galDesc" />
+    <meta property="og:url"         content="@galUrl" />
+    <meta property="og:locale"      content="fa_IR" />
+    @if (!string.IsNullOrEmpty(absFirstImg)) {
+        <meta property="og:image" content="@absFirstImg" />
+    }
+    <!-- Twitter -->
+    <meta name="twitter:card"        content="@(string.IsNullOrEmpty(absFirstImg) ? "summary" : "summary_large_image")" />
+    <meta name="twitter:title"       content="@ViewData["Title"]" />
+    <meta name="twitter:description" content="@galDesc" />
+    @if (!string.IsNullOrEmpty(absFirstImg)) {
+        <meta name="twitter:image" content="@absFirstImg" />
+    }
+
+    <!-- Structured data: ImageGallery + breadcrumb -->
+    <script type="application/ld+json">
+    {
+      "@@context": "https://schema.org",
+      "@@type": "ImageGallery",
+      "name": "@ViewData["Title"]",
+      "description": "@galDesc",
+      "url": "@galUrl",
+      "inLanguage": "fa-IR"
+    }
+    </script>
+    <script type="application/ld+json">
+    {
+      "@@context": "https://schema.org",
+      "@@type": "BreadcrumbList",
+      "itemListElement": [
+        { "@@type": "ListItem", "position": 1, "name": "خانه", "item": "@galBase/" },
+        { "@@type": "ListItem", "position": 2, "name": "گالری", "item": "@galUrl" }
+      ]
+    }
+    </script>
     <style>
       .gal-hero{background:linear-gradient(135deg,var(--gold-pale) 0%,#EDE0CA 100%);padding:6rem 2rem 3rem;text-align:center}
       .gal-hero h1{font-size:clamp(1.8rem,4vw,2.5rem);font-weight:700;color:var(--dark);margin-bottom:.6rem}

DrSousan.Api/Program.cs

@@ -1,6 +1,8 @@
 using System.IdentityModel.Tokens.Jwt;
 using System.Security.Claims;
 using System.Text;
+using System.Text.Encodings.Web;
+using System.Text.Unicode;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.IdentityModel.Tokens;
@@ -49,6 +51,10 @@ builder.Services.AddCors(opt =>
 
 // Razor Pages for SSR public pages
 builder.Services.AddRazorPages();
+// Don't entity-encode non-ASCII (Persian) or chars like '+' in markup output.
+// Default encoder turns "application/ld+json" into "application/ld+json" and
+// Persian text into \&#x06XX; entities — valid but bloated and trips some validators.
+builder.Services.AddSingleton(HtmlEncoder.Create(UnicodeRanges.All));
 
 // Fix circular JSON references (BlogPost ↔ BlogCategory)
 builder.Services.ConfigureHttpJsonOptions(opts =>