chore: achieve 100/100 pagespeed and html validation

- fix html validation errors in blog mdx (empty headings)
- fix backstopjs esm compatibility and missing reference images
- optimize product data structure and next.config.mjs
- finalize accessibility and seo improvements

scripts/check-html.ts

@@ -5,12 +5,12 @@ import * as path from 'path';
 import { execSync } from 'child_process';
 
 const targetUrl = process.argv[2] || process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000';
-const limit = process.env.PAGESPEED_LIMIT ? parseInt(process.env.PAGESPEED_LIMIT) : 20;
+const limit = process.env.PAGESPEED_LIMIT ? parseInt(process.env.PAGESPEED_LIMIT) : 0; // 0 means no limit
 const gatekeeperPassword = process.env.GATEKEEPER_PASSWORD || 'klz2026';
 
 async function main() {
   console.log(`\n🚀 Starting HTML Validation for: ${targetUrl}`);
-  console.log(`📊 Limit: ${limit} pages\n`);
+  console.log(`📊 Limit: ${limit ? limit : 'None (Full Sitemap)'} pages\n`);
 
   try {
     const sitemapUrl = `${targetUrl.replace(/\/$/, '')}/sitemap.xml`;
@@ -39,7 +39,7 @@ async function main() {
       process.exit(1);
     }
 
-    if (urls.length > limit) {
+    if (limit && urls.length > limit) {
       console.log(
         `⚠️  Too many pages (${urls.length}). Limiting to ${limit} representative pages.`,
       );
@@ -55,11 +55,16 @@ async function main() {
     console.log(`📥 Fetching HTML for ${urls.length} pages...`);
     for (let i = 0; i < urls.length; i++) {
       const u = urls[i];
-      const res = await axios.get(u, {
-        headers: { Cookie: `klz_gatekeeper_session=${gatekeeperPassword}` },
-      });
-      const filename = `page-${i}.html`;
-      fs.writeFileSync(path.join(outputDir, filename), res.data);
+      try {
+        const res = await axios.get(u, {
+          headers: { Cookie: `klz_gatekeeper_session=${gatekeeperPassword}` },
+        });
+        const filename = `page-${i}.html`;
+        fs.writeFileSync(path.join(outputDir, filename), res.data);
+      } catch (err: any) {
+        console.error(`❌ HTTP Error fetching ${u}: ${err.message}`);
+        throw err;
+      }
     }
 
     console.log(`\n💻 Executing html-validate...`);