fix(seo): resolve pagespeed insights performance and accessibility issues

- Add priority to hero image and replace css background-image with Next.js Image component for faster LCP
- Add aria-label and aria-expanded to mobile menu button in Navbar
- Add aria-label to social media links in Footer
- Replace css background-image with Next.js Image component in CTA and Services sections

app/[lang]/HomeClient.tsx

@@ -119,10 +119,14 @@ export default function HomeClient({ lang, dict }: { lang: string; dict: any })
 
       {/* ── Hero ── */}
       <section className="relative h-screen flex items-center justify-center overflow-hidden moy-grain">
-        <div
-          className="absolute inset-0 bg-cover bg-center bg-no-repeat scale-105"
-          style={{ backgroundImage: `url(${HERO_BG})` }}
-        >
+        <div className="absolute inset-0 scale-105">
+          <Image
+            src={HERO_BG}
+            alt="Moy Group Hero"
+            fill
+            priority
+            className="object-cover object-center"
+          />
           <div className="absolute inset-0 bg-gradient-to-b from-black/50 via-black/30 to-black/60" />
         </div>
 
@@ -246,9 +250,12 @@ export default function HomeClient({ lang, dict }: { lang: string; dict: any })
                 whileHover={{ y: -10 }}
                 className="group relative h-80 overflow-hidden cursor-pointer"
               >
-                <div
-                  className="absolute inset-0 bg-cover bg-center transition-transform duration-700 group-hover:scale-110"
-                  style={{ backgroundImage: `url(${service.bg})` }}
+                <Image
+                  src={service.bg}
+                  alt={service.title}
+                  fill
+                  sizes="(max-width: 768px) 100vw, (max-width: 1200px) 50vw, 20vw"
+                  className="absolute inset-0 object-cover object-center transition-transform duration-700 group-hover:scale-110"
                 />
                 <div className="absolute inset-0 bg-gradient-to-t from-[var(--color-moy-dark)] via-[var(--color-moy-dark)]/50 to-transparent" />
 
@@ -380,12 +387,14 @@ export default function HomeClient({ lang, dict }: { lang: string; dict: any })
 
       {/* ── CTA Banner ── */}
       <section className="relative py-32 overflow-hidden bg-[var(--color-moy-dark)]">
-        <div
-          className="absolute inset-0 bg-cover bg-center opacity-20"
-          style={{
-            backgroundImage: `url(https://images.unsplash.com/photo-1507525428034-b723cf961d3e?auto=format&fit=crop&q=60&w=1600)`,
-          }}
-        />
+        <div className="absolute inset-0 opacity-20">
+          <Image
+            src="https://images.unsplash.com/photo-1507525428034-b723cf961d3e?auto=format&fit=crop&q=60&w=1600"
+            alt="Moy Group CTA Background"
+            fill
+            className="object-cover object-center"
+          />
+        </div>
         <div className="absolute inset-0 bg-gradient-to-r from-[var(--color-moy-dark)] via-transparent to-[var(--color-moy-dark)]" />
 
         <div className="relative max-w-3xl mx-auto px-6 text-center">