feat(seo): add keywords meta tag support for improved SEO

- Introduced keywords property in layout and page server files to enhance SEO capabilities.
- Updated relevant components to include keywords in meta tags for better search engine visibility.

src/routes/+layout.svelte

@@ -20,6 +20,7 @@
     seoDescription?: string;
     socialImage?: string;
     robots?: string;
+    keywords?: string;
     jsonLd?: Record<string, unknown> | Record<string, unknown>[];
     breadcrumbItems?: { href?: string; label: string }[];
     topBanner?: {
@@ -185,6 +186,9 @@
   {#if seoDescription}
     <meta name="description" content={seoDescription} />
   {/if}
+  {#if pageData?.keywords}
+    <meta name="keywords" content={pageData.keywords} />
+  {/if}
   <link rel="canonical" href={canonical} />
   <!-- Open Graph -->
   <meta property="og:type" content="website" />

src/routes/+page.server.ts

@@ -112,5 +112,6 @@ export const load: PageServerLoad = async ({ locals, fetch }) => {
       : siteName,
     seoDescription: page ? (page.seoDescription ?? page.subheadline ?? '') : '',
     robots: (page as { seoMetaRobots?: string } | null)?.seoMetaRobots ?? undefined,
+    keywords: (page as { seoKeywords?: string } | null)?.seoKeywords ?? undefined,
   };
 };

src/routes/[...slug]/+page.server.ts

@@ -79,6 +79,7 @@ export const load: PageServerLoad = async ({ params, locals, fetch }) => {
     seoTitle: page.seoTitle ?? page.headline ?? page.linkName ?? slug,
     seoDescription: page.seoDescription ?? page.subheadline ?? '',
     robots: (page as { seoMetaRobots?: string }).seoMetaRobots ?? undefined,
+    keywords: (page as { seoKeywords?: string }).seoKeywords ?? undefined,
     breadcrumbItems: [
       { href: '/', label: 'Start' },
       { label: page.headline ?? page.linkName ?? page.slug ?? page._slug ?? slug },

src/routes/post/[slug]/+page.server.ts

@@ -210,6 +210,7 @@ export const load: PageServerLoad = async ({ params, locals, url }) => {
     seoDescription: postDescription,
     socialImage: postSocialImageAbs ?? postImageUrl ?? undefined,
     robots: (post as { seoMetaRobots?: string }).seoMetaRobots ?? undefined,
+    keywords: (post as { seoKeywords?: string }).seoKeywords ?? undefined,
     jsonLd,
     breadcrumbItems: [
       { href: '/', label: 'Start' },