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

components/ContactForm.tsx

@@ -148,7 +148,6 @@ export default function ContactForm() {
             autoComplete="name"
             enterKeyHint="next"
             onFocus={() => handleFocus('contact-name')}
-            aria-label={t('form.name')}
             required
           />
         </div>
@@ -163,7 +162,6 @@ export default function ContactForm() {
             enterKeyHint="next"
             placeholder={t('form.emailPlaceholder')}
             onFocus={() => handleFocus('contact-email')}
-            aria-label={t('form.email')}
             required
           />
         </div>
@@ -176,7 +174,6 @@ export default function ContactForm() {
             enterKeyHint="send"
             placeholder={t('form.messagePlaceholder')}
             onFocus={() => handleFocus('contact-message')}
-            aria-label={t('form.message')}
             required
           />
         </div>

components/Footer.tsx

@@ -19,6 +19,7 @@ export default function Footer() {
       <div className="absolute top-0 left-0 w-full h-px bg-gradient-to-r from-transparent via-white/20 to-transparent" />
 
       <Container>
+        <h2 className="sr-only">Footer Navigation</h2>
         <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-12 gap-16 mb-20">
           {/* Brand Column */}
           <div className="lg:col-span-4 space-y-8">

components/RequestQuoteForm.tsx

@@ -172,7 +172,6 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
             onChange={(e) => setEmail(e.target.value)}
             onFocus={() => handleFocus('quote-email')}
             placeholder={t('email')}
-            aria-label={t('email')}
             className="h-9 text-xs !mt-0"
           />
         </div>
@@ -186,7 +185,6 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
             onChange={(e) => setRequest(e.target.value)}
             onFocus={() => handleFocus('quote-request')}
             placeholder={t('message')}
-            aria-label={t('message')}
             className="text-xs !mt-0"
           />
         </div>

components/home/ProductCategories.tsx

@@ -43,7 +43,7 @@ export default function ProductCategories() {
 
   return (
     <Section className="bg-neutral-light py-0 md:py-0 lg:py-0 -mt-px">
-      <h2 className="sr-only">{t('title')}</h2>
+      {t('title') && <h2 className="sr-only">{t('title')}</h2>}
       <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4">
         {categories.map((category, idx) => (
           <Link