feat(frontend): Implement SEO improvements

- Reorder inscription titles to lead with descriptive text
- Enrich inscription meta descriptions with provenance, date, material
- Add Open Graph tags and canonical URL to root layout
- Fix non-standard meta tags (tags → keywords) across all pages

Author: jmiguelv

frontend/src/routes/+layout.svelte

@@ -29,10 +29,20 @@
 
 <svelte:head>
 	{#if $page.data.title}
-		<title>{config.title} | {$page.data.title}</title>
+		<title>{$page.data.title} | {config.title}</title>
 	{:else}
-		<title>{config.title}</title>
+		<title>{config.title} — {config.subtitle}</title>
 	{/if}
+	<meta name="description" content={config.description} />
+	<link rel="canonical" href={`${config.url}${$page.url.pathname}`} />
+	<meta property="og:site_name" content={config.title} />
+	<meta property="og:type" content="website" />
+	<meta property="og:url" content={`${config.url}${$page.url.pathname}`} />
+	<meta
+		property="og:title"
+		content={$page.data.title ? `${$page.data.title} | ${config.title}` : config.title}
+	/>
+	<meta property="og:description" content={config.description} />
 </svelte:head>
 
 <div class="layout">

frontend/src/routes/bibliography/+page.svelte

@@ -89,7 +89,7 @@
 <svelte:head>
 	<title>Bibliography | {config.title}</title>
 	<meta name="description" content="Publications cited across the inscriptions in ISicily corpus" />
-	<meta name="tags" content="bibliography, publications, {config.title}" />
+	<meta name="keywords" content="bibliography, publications, {config.title}" />
 </svelte:head>
 
 <article>

frontend/src/routes/bibliography/[slug]/+page.svelte

@@ -11,7 +11,7 @@
 <svelte:head>
 	<title>{zotero.title} | {config.title}</title>
 	<meta name="description" content={zotero.title} />
-	<meta name="tags" content="bibliography, {zotero.title}" />
+	<meta name="keywords" content="bibliography, {zotero.title}" />
 </svelte:head>
 
 <article>

frontend/src/routes/inscription/[slug]/+page.svelte

@@ -136,10 +136,21 @@ ${changeDate ? `Last revised: ${changeDate}.` : ''}
 />
 
 <svelte:head>
-	<title>{metadata.file}: {metadata.title} | {config.title}</title>
-	<meta name="description" content={metadata.title} />
+	<title>{metadata.title} ({metadata.file}) | {config.title}</title>
 	<meta
-		name="tags"
+		name="description"
+		content={[
+			metadata.title,
+			metadata.places?.[0]?._ ? `Found at ${metadata.places[0]._}` : null,
+			metadata.date?._ ? `Date: ${metadata.date._}` : null,
+			metadata.material?._ ? `Material: ${metadata.material._}` : null,
+			metadata.textLang?._ ? `Language: ${metadata.textLang._}` : null
+		]
+			.filter(Boolean)
+			.join('. ')}
+	/>
+	<meta
+		name="keywords"
 		content="sicily, inscription, {metadata?.textLang?._}, {metadata?.type?._}, {metadata
 			?.objectType?._}"
 	/>

frontend/src/routes/museum/+page.svelte

@@ -93,7 +93,7 @@
 		name="description"
 		content="Museums and repositories holding the inscriptions in ISicily corpus"
 	/>
-	<meta name="tags" content="museums, repositories, {config.title}" />
+	<meta name="keywords" content="museums, repositories, {config.title}" />
 </svelte:head>
 
 <article>

frontend/src/routes/museum/[slug]/+page.svelte

@@ -12,7 +12,7 @@
 <svelte:head>
 	<title>{museum.name} | {config.title}</title>
 	<meta name="description" content={museum.name} />
-	<meta name="tags" content="museum, inscriptions, {museum.name}" />
+	<meta name="keywords" content="museum, inscriptions, {museum.name}" />
 </svelte:head>
 
 {#snippet address(/** @type {import('./$types').PageData['museum']['location']} */ location)}