feat: improve SEO with locale-specific metadata, structured data, and keywords

- Add locale-specific title/description for DE and EN homepage
- Expand keywords with local SEO terms (Webentwicklung Osnabrück, Informatik, etc.)
- Add WebSite schema and enhance Person schema with knowsAbout, alternateName
- Add hreflang alternates for DE/EN
- Update projects page with locale-specific metadata
- Keep visible titles short, move SEO terms to description/structured data

app/_ui/HomePageServer.tsx

@@ -31,20 +31,41 @@ export default async function HomePageServer({ locale }: HomePageServerProps) {
   return (
     <div className="min-h-screen">
       <Script
-        id={"structured-data"}
+        id={"structured-data-person"}
         type="application/ld+json"
         dangerouslySetInnerHTML={{
           __html: JSON.stringify({
             "@context": "https://schema.org",
             "@type": "Person",
             name: "Dennis Konkol",
+            alternateName: ["dk0", "denshooter"],
             url: "https://dk0.dev",
             jobTitle: "Software Engineer",
+            description:
+              locale === "de"
+                ? "Software Engineer & Webentwickler in Osnabrück. Webentwicklung, Fullstack-Apps, Docker, Next.js, Flutter."
+                : "Software Engineer & Web Developer in Osnabrück, Germany. Web development, fullstack apps, Docker, Next.js, Flutter.",
             address: {
               "@type": "PostalAddress",
               addressLocality: "Osnabrück",
-              addressCountry: "Germany",
+              addressRegion: "Niedersachsen",
+              addressCountry: "DE",
             },
+            knowsAbout: [
+              "Webentwicklung",
+              "Web Development",
+              "Next.js",
+              "React",
+              "TypeScript",
+              "Flutter",
+              "Docker",
+              "DevOps",
+              "Self-Hosting",
+              "CI/CD",
+              "Fullstack Development",
+              "Softwareentwicklung",
+              "Informatik",
+            ],
             sameAs: [
               "https://github.com/Denshooter",
               "https://linkedin.com/in/dkonkol",
@@ -52,6 +73,20 @@ export default async function HomePageServer({ locale }: HomePageServerProps) {
           }),
         }}
       />
+      <Script
+        id={"structured-data-website"}
+        type="application/ld+json"
+        dangerouslySetInnerHTML={{
+          __html: JSON.stringify({
+            "@context": "https://schema.org",
+            "@type": "WebSite",
+            name: "Dennis Konkol",
+            alternateName: "dk0.dev",
+            url: "https://dk0.dev",
+            inLanguage: ["de", "en"],
+          }),
+        }}
+      />
       <Header locale={locale} />
       {/* Spacer to prevent navbar overlap */}
       <div className="h-24 md:h-32" aria-hidden="true"></div>